Final Report March 2000

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10.3.7 Singapore

Singapore is a city-state with a population of about 3.6 million as of 1997. About 11% of the land area of approximately 648 sq. km is used for roads and road-related facilities. With limited land for road expansion, it was necessary that attractive and sustainable alternative modes should be provided.

Managing the travel demand is a key element in Singapore. An integrated transport planning strategy reduces trips to CBD areas. A vehicle quota system has managed the growth in car ownership to a manageable level. Singapore manages the usage of vehicles through its road pricing policies. However, the demand management policies can only be effective when an efficient public transport alternative exists.
High-density urban development is closely integrated with the transit system. Singapore’s basic urban structure plan shows a series of radial and circumferential mass transit lines with major and minor sub-center nodes developed at high densities around the intersection of all these lines.
Like other cities, Singapore once faced the dilemma of the automobiles. However, they decided to provide more for transit than for the cars. Currently, Singapore has remarkably successful transit systems and very low car usage. The transit system is well scheduled, rapid and comfortable and flexible. Singapore’s Mass Rapid Transit (MRT) comprises 48 stations and 83 km of tracks. In 1990, about 0.53 million passengers used the MRT on weekdays and this had increased to 0.88 million passengers in 1996. To make the MRT system more attractive mode for car users, park-and ride facilities have been provided at several stations. Passengers information systems to provide advanced information regarding train arrival times, disruptions and delays are installed at some of the MRT stations. To facilitate commuter movement between MRT stations and nearby buildings or bus stops, covered link-ways have been provided. Also, pedestrian overhead bridges or underpasses have been provided where there is a high volume of commuter traffic. The light rail transit (LRT) is to complement the MRT as a high-capacity feeder system. An automated LRT system is being constructed in a public housing estate and connected to a MRT station with 7.8km long and 13 stations.
3,300 public buses are still the backbone of the public transport system. Many of these buses are air-conditioned to make travelers more comfortable. Furthermore, most of the buses have new features, such as the lower and wider entrance and exit pathway, for added convenience and safety of bus passengers. The pathway does not have more than two steps to facilitate easier movement for boarding and alighting passengers.

10.3.8 U.S.A.

Most of North American cities have grown up in the automobile era. Many cities in the central and western areas are post-1940s cities. Currently, after 50 years of automobile-based growth, such cities have spread almost to the limits of comfortable car commuting. Their automobile-based, and low-density suburbs have become a normal living environment for their citizens. Therefore, in most of the cities, transit is in decline. The percentage of people using transit for the work trip has declined by 60 percent, though public subsidies began on a large scale in the 1960s,. The decline has quickened in the 1990s, with a 10 percent drop in per capita ridership in just four years.

Portland in Oregon is an exception. In 1970s when the Mt. Hood expressway passing through the Portland was planned, the community decided not to build the expressway but instead to go for a LRT called MAX. Many transport experts thought that LRT couldn’t get people out of their cars in a modern city and that LRT would fail. Currently, the LRT has become a popular new idea of transport in America. It embodies a technology once referred to as streetcars. Its popularity derives from many factors. One of that is the sense of permanence it conveys. LRT is expected to anchor other public and private initiatives designed to sustain an already healthy urban environment or to invigorate one that has been in decline. Thus, LRT represents an economic development strategy directly, as well as being a conveyor of commuters and other city travelers. LRT has a capital cost that is disadvantageous compared to the bus. It costs less, however, than its grade-separated heavy rail transit such as a subway. Lacking grade-separation, however, its speed tends to be slower and it is expected to conflict with other traffics with adverse service and safety impacts.
Despite of its very high cost, grade-separated heavy rail systems continue to have strong support. The Federal Transit Administration (FTA) list of new rail projects for light, commuter and heavy rail extends currently to 46 cities. In some cases the project proposals are for extensions to existing systems, in some for entirely new systems. Heavy rail development can accompany a companion development of LRT, though it might require a very long-run strategy. In the San Francisco Bay Area, 24 years after the first service, a number of development projects are springing up adjacent to stations that seemed to have little community impact in the early years.
The MAX is a success story of LRT in North America^³⁴. It has twice the patronage of the bus system, and a large off-peak usage by families going into the city. Now, so many other corridors wish to build MAX instead of a freeway. There have been several other important side effects. One is the city center has come alive after the business community recognized the opportunity provided by MAX. Street lanes in downtown have been taken away from auto traffic on the streets along which MAX runs. The space has been used to provide an exclusive right-of way for the trains and to widen the sidewalk for the pedestrian. Bus priority streets running across MAX lines have also limited cars to one lane. The streets have been significantly improved with generous tree planting and with high quality bus shelters incorporating comprehensive transit system information. The city center is one of the most attractive in the U.S.
The downtown’s percentage of the metropolitan area’s total retail turnover increased from 5% to 30% because of a combination of enhanced transit access, more human attractions, and extra housing, rather than more road space and parking. A central-city car park was disappeared and replaced with a public meeting place, and a downtown freeway was changed to a park. The central-city employment rose 50%, but there was no increase in car commuting to the city center. The city has now recognized that MAX provides the opportunity to evolve an integrated approach to land development. Portland has created a plan to curtail outer area growth and redirect it to urban redevelopment around transit stops. 85% of all new growth must now be within five minutes walk of a designated transit stop. Portland has shown that it has a direction based on reconnecting its city to good transit services and that it is not inevitable for the automobile to continue to dominate the city.

Ch.11 Improvement of Transport Management, Traffic Operation and Control

11.1 Policy Alternatives of Travel Demand Management(TDM)

A paradigm shift in urban transportation planning from the conventional demand-following approach to an integrated package approach has been proceeding since the early 1990s. In other words, transportation policies in many countries tend to be changed from a "predict and provide" approach to a "predict and prevent" approach.

TDM has been succinctly described as an art of influencing traveler behavior for the purpose of reducing or redistributing travel demand in space and time. TDM programs are designed to maximize the people-moving capability of the transportation system by increasing the number of persons in a vehicle, or by influencing the time or need of travel. To accomplish these types of changes, TDM programs must rely on incentives or disincentives to make these shifts in behavior attractive. An effective TDM program may be one that provides alternatives to the travelers and then reinforces the TDM travel decision by implementing incentives and disincentives (US DOT, 1994).
TDM strategies include improvements in alternative modes of transportation; financial or time incentives for the use of these alternative modes; information dissemination and marketing activities to promote these modes; and supporting services that make the use of more convenient alternatives or that remove psychological impediments to their use. TDM programs can also include alternatives to influence when travel occurs during a day, or if it occurs at all on certain days. Despite of the lack of effective actions in most countries to reduce car use, it is widely believed that private car users do not pay the external costs which are borne by others in the form of road casualties, noise, pollution, taxation to provide the necessary infrastructure, etc. It is also generally recognized that increasing car travel costs has a greater impact on reducing car usage, and hence on reducing vehicle emissions, than lowering fares or improving public transport service.
It must be realized that the application of severe restraint measures might, in some circumstances, have unwanted side effects, e.g. in driving out businesses or encouraging out-of-town development. Limiting the parking supply, usually in conjunction with raising the parking fees, has been one of the most common methods of restraint in almost all cities. Rather, using the pricing mechanism to ration scarce parking facilities seems to be more efficient. Limiting parking supply to company employees, however, can be a very effective way of influencing the modal split. Redistributing road space in favor of public transport and pedestrians can restrict car movements. Allocating more time at traffic signals to pedestrians and public transportation might strengthen the impact on the car use. Segregated tram tracks, bus lanes and bus priority at traffic signals, combined with a reduction in parking supply, can result in a dramatic drop in the number of trips by private car. Employer-based TDM programs have helped to reduce spot congestion and shorten delays at intersections.

TDM measures incorporated into local traffic management plans have also helped to moderate the growth of congestion in suburban downtown. TDM program in the form of "traffic calming" measures have proved effective in reducing unwanted car traffics and controlling aggressive driving behaviors in residential neighborhoods. Carpooling has some benefit over vanpooling or transit. The benefit is that carpooling appeals to market segments that rely heavily on vehicles, characteristics of the single occupant vehicle, with door-to-door convenience, relaxing environment, and commitment to schedule.

To be more efficient, TDM policies need to provide incentives, or "carrot" measures, to encourage and induce changes in travel behavior. More strict enforcement of parking and other traffic regulation is an indispensable element as the push "stick" measures. The involvement and participation of drivers, employers and the community is important. Therefore, the local government should play a leading role to formulate appropriate mechanisms to involve them from the early stages of policy-making.
Recently, a new approach to TDM has been introduced as a mobility management. "Mobility Management" is a series of strategies aimed at reducing the amount of road traffic attracted to or generated by particular sites, by encouraging changes in behavior on the part of the organizations and individuals who work there or go there as customers or suppliers. Three main activities of mobility management are:
 To provide improved information to travelers and freight operators,

 To influence the choice of transportation modes in favor of more sustainable modes,

 To encourage an integrated land-use /transportation planning process^³⁵.

11.2 Mitigation of Traffic Congestion by Traffic Operation and Control

Mitigating traffic congestion is one of the ways of making the road system more efficient. The ways of making more efficient use of the road systems have been investigated through the analysis and conduct of various policies in many countries. The policies to efficiently use road systems include traffic management, providing trip information, congestion pricing, HOV strategies, bus priority measures, traffic control, portable traffic management, etc.

11.2.1 Policies Conducted in the APEC Region

Some countries have been successful in maximizing the usage of the existing roadway systems by implementing diverse policies. Traffic management strategies have been very effective in countries such as Australia, Japan, South Korea and U.S.A. Transportation Management Centers (TMCs) have played an important role in managing traffic flows. Major traffic components like travel time, delays, speeds, and traffic accidents have been monitored and controlled by the operation of TMC. From the experiences of transportation management policies between the APEC countries, it could be known that the investment in traffic facilities such as TMC, sensors, cameras, and so on is essential to efficiently utilize the roads. It has also been shown that trip information is important to provide alternative routes to reduce congestion on the roadways. Advanced trip information systems in major cities of the U.S.A. have resulted in mode shifts, anxiety-reduction and savings in travel time. Trip information and traffic management equipped with intelligent traffic control schemes have been proven to be critically useful tools in using roads effectively and efficiently.

By introducing congestion pricing and HOV lanes, the attitude of dealing with the roadways has been changed in terms of trip purpose and travel routes. Those policies have been proved to successfully distribute traffics in the road networks in the experiences of Hong Kong, South Korea, and the U.S.A. For instance, a congestion pricing has been executed on the bridges towards CBD in New York City. It has been very effective in reducing the traffic congestion in downtown, thus managing the existing roadways in a proper manner. In Korea, congestion fees are being collected at the entrances of tunnels toward old CBD areas, diverting the vehicles to the alternative routes and relieving the traffic congestion in corridors near the tunnels.
In order to efficiently conduct congestion pricing policy in a specific location, the traffic countermeasures need to be established to make the traffic flow smooth in the whole network. Bus priority lane policy has also worked effectively in reducing traffic congestion in Hong Kong, New Zealand, and South Korea. Seoul has experienced the faster travel time and the less congestion as a result of bus priority lanes. The adjustment of operation time becomes a vital factor to keep the traffic on the other lanes.
Traffic signal control systems such as SCOOT, SCATS, and ATSAC have performed satisfactorily to decrease travel time, vehicle stops, and delays in several APEC countries. As the traffic control system package was so successful in Hong Kong, there are plans to extend it to more towns. SCATS have worked excellently in treating the unexpected delays, queues, or congestion for the main arterials in Sydney. Advanced traffic signal systems in the U.S.A. have also showed good capabilities in improving travel time, travel speed, and delays, compared to the traditional traffic signal system. The countries mentioned above are good examples of effectively managing existing roadway systems with the help of advanced traffic operation software, without investing much money to build new roads.

11.2.2 Promoting Directions and Strategies
Traffic Dispersion and Incident Management Through Traffic Information
In order to use the roads efficiently, a traffic information system, which provides the traffic situations in either on-line or pre-time ways, is essential. Traffic information under the unexpected situations on the roadway plays a role in dispersing traffics into less congested roads. Then, road networks can be utilized efficiently without vacant roadways. Also, pre-timed information on congested networks helps the car owners not to bring their vehicles onto the roadways. The car owner may take a public transportation mode or change his travel schedule.
The increase of transit users would virtually result in reducing the use of private cars. The following detailed subjects could be applied to conduct this strategy:

Efficient and systemic share of the traffic information: reinforcement of administrative correlation between police agencies, local governments, media, and other related organizations.

 Expansion of media groups delivering traffic information

 Implementation of transportational countermeasures in case of incidents:

 Building of low-cost traffic information system

 Improvement of public transportation information system:

Providing alternative routes for expected incidents such as road construction works, suspension of traffic or/and events are important. Fixed traffic signs or variable message signs could be installed in front of the work site to divert the vehicles on the vacant roads. Moving the work time to night is also effective to optimize the use of the roads by minimizing the bottlenecks on the roadways. Unexpected incidents such as disorder of traffic signals at intersections, sudden congestion by traffic violations, and usual accidents may be prevented by assigning the more personnel and budget. Introduction of the traffic-responsive signals could be effective to control traffic timely under incidents. Connection of the each signal system in a specific corridor is required to control the traffic continuously and consistently.
Operation of integrated transit information center covering buses, subways, and taxis would be the most effective. The transit center must be co-related with the traffic center managing traffics on the roadway. A transfer station transmitting various traffic information is a particularly good place for controlling the traffic demand on the roadways. Taxis will effectively use the traffic information providing the real-time traffic condition on the network to take alternative routes to prevent the congestion.
Enhancement of traffic signal system operations
There are many cost-effective ways to enhance traffic signal systems.
First, the traffic signal systems should be placed appropriately considering the characteristics of the network. Cities in the APEC member countries operate fairly diverse traffic signal systems such as Time of Days (TOD), traffic-responsive, and so forth. Operating different systems in a particular network makes both the traffic operators and drivers confused. The consistent placement of signal system in a network plays a critical role in proper roadway management. In other words, the traffic signal system within a particular corridor, including similar traffic flow patterns, needs to have the same types of operation algorithm. As a matter of fact, managing the roads with the TOD method is only useful to control the traffic in a decent manner in cases without incidents. The TOD method with well-analyzed traffic cycle is good enough to handle the recurring congestion on the usual network in cities. However, as most cities tend to be affected with sudden congestion caused by accidents or traffic violations, a better traffic signal system is needed to solve those congestion problems.
Second, the operation level of the traffic management center should be improved with respect to the collection of traffic data, analysis of the traffic flow, and delivery of the information to the drivers. The TMC(Transportation Management Center), which incorporates data collection, traffic analysis and information delivery, is operated very usefully to use the existing roads in a few countries such as Australia, Japan, South Korea, and the U.S.A. It is desirable that the advanced traffic signal systems are elaborately harmonized with the TMC. For real-time traffic control, various types of electronic facilities are required. It is important to incorporate related agencies for the traffic signal systems and traffic management.
Improvement of traffic signs and markings
It is not easy for a regular traveler to quickly find his destination in a complicated network. Wasting time to find out the places destined is a huge obstacle to use the existing roadway efficiently. Traffic signs and road markings play a vital role in distributing the vehicles impartially throughout the whole network. The number of signs per kilometer has to be evaluated to examine the efficient road usage. A lack of traffic signs may lead the drivers into congested roadways. The location and arrangement of traffic signs is also fairly important to provide traffic information properly. Optimal contents of locations and their arrangements would help select the optimal route in terms of travel time and distance. Reliability, co-ordination, liaison on the signs and road markings are essential in using the roads efficiently. Unifying the government and related agencies administratively makes improving the road sign system in a particular network or corridor much easier. The following details are available to implement better traffic sign systems.
 Suggest the specific standards for contents, placement, and location of road signs.

Introduce the road numbering system considering the geometric characteristics of each roadway

 Integrate the administrative agencies handling traffic signs
Implementation of bus priority lanes
Bus priority lanes have been fairly successful in a few countries. It has contributed in preventing unnecessary congestion resulting from the weaving and passing of the vehicles. Speed and travel time has been greatly improved on the network after the implementation of the bus priority systems.

There may be a negative impact of the bus priority system, in that it might decrease the capacity of the roads and increase the congestion at other lanes. In order to minimize the negative impact, it is important to designate the location and operating time of the bus priority lanes properly. If there are not buses good enough for the bus priority on the roadway link, it is not necessary to designate bus priority lanes. Consistency of the priority lanes is very important to prevent isolation from the other vehicles. Traffic signs and road marking indicating bus priority lanes need to be clear for drivers. The following strategies are required to operate the bus priority lane policies more effectively.

Establishment of roadway facilities in the existing bus priority lanes: Differentiation of bus lanes by coloring and/or adding more traffic signs
Introduction of bus priority traffic signals at intersections: Extension of green time by detecting the presence of buses (connection of bus priority lane with priority signals result in reducing travel time for bus). Early-start phase, bus-only phase, and pre-signal systems are possible.
Restriction of entrance and exit from/to local roads: expansion of one way roads for assuring the sequence of priority lanes
Rigid enforcement of regulation: protect the interruption into the priority lanes by private vehicles, install the automated enforcement system including advanced cameras, detectors, and variable message signs
Establishment of an administrative agency for operating the bus priority lane for the jobs such as the operation planning, maintenance, and enforcement.
Securing of investment resources
Utilization of intelligent public transport systems: bus arrival guidance system, general traffic information, integrated fare collection systems are available

Reinforcement of the role of arterial roads
The speed of vehicles on arterial roads tends to decrease over time. It means that arterial roads do not play their original role. Congestion or bottleneck phenomenon on the arterial roads seriously hurts the traffic flow on all the roadways along the whole network. The phenomena create delays, decreased travel time, and reduced vehicle speed throughout the whole network. It can even be a main factor causing accidents. In order to normalize the traffic flow along with the arterial roads, the following strategies could be applied.

Install turning traffic control systems: to adjust the green signal time on the entrance direction to manage properly the traffic volume on the arterial roads.
Introduce ramp-metering system
Restrict to the low-speed vehicles, such as trucks, into the arterial roads: to protect the cause of accidents by the mixed traffic in high and low speed.
Introduce High Occupancy Vehicles (HOV) policy: to induce the travelers give up driving their own cars.
Introduce the traffic information guidance system: to indicate the recent traffic conditions, traffic accident information, lane use guidance, weather/roadway information before entering into the arterial roads.

Improvement of roadway operation system
When main traffic corridors are heavily congested, the local roads could be consequently affected by the congestion. In large cities, the usage of local roads is very poor. This is due to the inferiority of the roadway condition. The consistent and unified layout of local roads would increase their usage. Specific parking policy on the local roads must coincide with vehicle movements. To make the local roads replace the main streets in cases of congestion, the following various strategies are possible.
 Enforcement of parking violation: install guidance signs indicating clear "no parking area".

 Restriction of piling-up or heaping on the streets

 Installation of the traffic safety facilities dividing vehicles into pedestrians

 Removal of the traffic obstacles

 Installation of bump / hump to decrease speeds of the vehicles passing
One-way system is a very effective way of reducing congestion and accidents on the roadway without spending excessive costs. Generally, it was reported that implementation of an one-way system results in a 10-50% reduction in travel time, 10-40% reduction of traffic accidents, and a 10-30% increase in traffic volume. It is necessary to install the traffic signs, road markings, and traffic signal adjustment for the operation of road system management scheme. Implementation of an one-way system along the continuous roadways would result in more smooth traffic flow on the network. This could be easily applied to the existing roads assuring the reduction of conflicts between vehicles. To find out the optimal corridor for application of an one-way scheme, accessibility of public transport and its impact on commercials in the vicinity has to be considered seriously.

Suggestion of a traffic management scheme during road construction
In case of unavoidable road construction work, it is natural that traffic flow is hindered due to the narrowed roadways. Accidents between vehicles and pedestrians are frequent around construction work areas. Adverse road conditions may also induce traffic accidents. It means that the roads are not used appropriately. In order to keep the traffic flow in normal under the poor road conditions, the followings can be applied.

Elastic operation of work time: night is usually chosen: sometimes it depends on the local characteristics, traffic situations, and weather condition.
Minimize the work areas on the roadways: areas occupied could be reduced by advanced construction technology.
Enhance the pedestrian environment: to reduce traffic accidents involving pedestrians.
Operate an independent administrative agency to control the traffic under the construction work.
Adjust the traffic signal phases depending upon the changed road conditions: to develop the better traffic control techniques.

Operation plans of the policies
Each of the policies proposed may need different conditions, budgets, and duration to implement successfully. Even the importance of each policy in terms of the given social and economic situations in each of the countries may be much different one another. Strategies could be different depending on the economic size of the country. In improving roadway usage, advanced countries may have different priorities from undeveloped countries. Some operation plans are proposed in the following table.

Traffic Operation Plans in Short-, Mid-, and Long-Term

Short-Term

Mid-Term

Long-Term

Extend traffic control system into various regions

Improve traffic sign and marking systems

Implement advanced road operation scheme accounts for the roadway characteristics

Establish diversion strateg-ies and incident management schemes

Enhance traffic signal systems

Develop versatile trip information system to adapt all the areas

Build Transportation Management Center equipped with road surveillance

Incorporate traffic information system with public transport information system

Develop a new and intelligent transport mode

Upgrade the roadway system itself

Execute the efficient transportation demand management schemes to optimize travel

Develop transportation planning methodology to minimize travel distance

11.3 Case Study 1: Traffic Management System in the USA

11.3.1 Transportation Management Centers(TMC)

Roadway management has been practiced for approximately 100 years in the USA. There are several management endeavors that continue to occupy the attention of transportation engineers. These include efforts to improve traffic flow by ramp metering of freeways, synchronization of signals on a major arterial, as well as techniques to control on-street parking and left-turn interference with through-traffic. The roadway maintenance scheduling is also a critical facets considered to be subject to management intervention. More recently incident management has been added to the list. As much as fifty percent of traffic delays have been attributed to accidents, flat tires, stalled cars or other such interruptions to the normal flow of traffic. The introductions of traffic surveillance systems and freeway service patrols have been responsive to these mounting problems.

In order to optimize the efficiency of the existing road systems and the above traffic management tactics, the Transportation Management Center (TMC) has become the focal point since 1960s. This was because traffic volume rapidly increased and the construction of new road systems took long times. The TMC brings together the components, programs, and strategies that comprise incident and congestion management. It links various elements of Intelligent Transportation Systems(ITS), such as variable message signs, closed circuit video equipment, roadside traffic monitors, etc., enabling decision makers to identify and react timely to an incident on the roadways. By obtaining real-time roadway information from the TMC, drivers can avoid or divert the congested areas. Therefore, the whole network is efficiently utilized through the proper assignment of the vehicles on the roadways.
The Transtar, TMC in Houston, controls 5,436 square miles with a population of 4.0 million. The center manages 53 ramps, a 63-mile HOV lane system, and 22,800 traffic signals with CCTV, VMS, and ITS facilities. A Transportation Management Center in Minneapolis metropolitan areas plays a vital role in incident management. TMC broadcasts traveler information via roadway advisory radio to minimize the impacts of the incidents that happened suddenly on the roadway. They also coordinate their activities with the State patrol, county and city traffic engineers, and transit buses to keep traffic moving on the roadways during major incidents. The benefit of the TMC has recently been quantified by the Minnesota DOT in terms of congestion and safety reduction. Accident rates were decreased by 25%, and there was a 20-minute reduction in response time to incidents. Average speed increased by 35% during rush hours and the capacity of roadways increased by 22%.
The TransGuide system of the Texas Department of Transportation focuses on the incident management, rather than congestion management. The TransGuide control room monitors traffic conditions and traffic signals, and allows rapid response to accidents and emergencies using data from roadside sensors. The communication systems use fiber optic cables strategically throughout the system. According to a before & after study conducted for the TransGuide system, focusing on safety, incident management, and driver understanding and utilization, it was found that the total accident rates decreased 15 percent for roadways covered by the system in 1995. Accident rates for freeways in San Antonio not covered by the TransGuide system experienced an increase of 4 % in 1995. Moreover, the average response time to incidents was improved 19% for minor incidents and 21% for major incidents in 1995, even though police and motorist assistance levels remained the same. Survey results indicated a high driver understanding of the systems. Atlanta, Chicago, Seattle, and Milwaukee are also operating TMC to facilitate the efficient use of the road system.
Portable Traffic Management Systems (PTMS), also called Movable Event Management Systems (MEMS), consists of easily portable traffic control and management devices. PTMS components provide surveillance, traffic control, traffic management, and advisory functions for special events such as a concert or a sports event which generates intense traffic and parking demands over a relatively short, but predictable period of time. Typical components of PTMS include a mobile command post such as a van, which controls PTMS components and receives the data from the other components, portable closed circuit video cameras, portable variable message signs, highway advisory radio, and portable traffic signals for safe access and egress control of parking lots. The function of PTMS is to keep motorists informed of congestion, available parking locations, alternative routes, or any other information which would minimize delays associated with arriving at, or leaving, the special events. The merits of the program are easy implementation with a two to three hour set up time and reliability of the system.

11.3.2 Trip Information System
Trip information provides information on traffic condition and transit level of service. There are two kinds of information; pre-trip information and real-time information. Pre-trip information has more capability than real-time information to escape traffic congestion caused by incidents. It is due to their different characteristics. While pre-trip information gives travelers diverse opportunities to take routes before starting the trip, real-time information does not contain alternative routes for avoiding unexpected congestion. For travelers, pre-trip information is more reliable and strategic than real-time information. Because of this, it may be mentioned that providing pre-trip information makes better use of the roadways. The objective of pre-trip information is to notify traffic information to potential travelers into the network, and they could best evaluate their travel options before they commit themselves to a specific route, mode, time-of-day, or even decide whether to travel or not. Pre-trip traffic information delivers real-time customized information to several different travelers.

Four pre-trip services are now operated in the USA: the Los Angeles Smart Traveler, the Boston SmarTraveler, TravInfo, and the provision of traffic information through the World Wide Web. The Los Angeles Smart Traveler system offers information on real-time traffic conditions, transit schedules and route planning, and ridesharing services, via public kiosks, telephones, and PC modem links. The Boston SmarTraveler has been in operation since 1993 by providing real-time, route-specific traffic and transit information in the Boston metropolitan area. It covers approximately 1,400 square miles and 2 million drivers. TravInfo installed in the San Francisco bay area utilizes loop detectors and CCTV to estimate congestion levels, speed, and incident data for about 150 freeway miles.
Travelers can access real-time traffic information through the internet systems in metropolitan regions of the United States. The information is displayed using a map, which is color-coded to identify the congestion levels, running speed, or incident locations in the network. It also provides photographs from CCTV cameras, updating them as frequently as every few minutes. It is especially useful in obtaining detailed information regarding incidents, including a description of the incident, its status, and the estimated clearance duration. A few sites provide trip planning tools: travel time prediction, route planning between any given origin and destination in the concerned network. The four services are mostly implemented through a partnership of public agencies, research institutions and private firms, under the leadership of federal government and local metropolitan transportation commission.
Usage of Boston SmarTraveler has increased over time since 1994. It peaks during winter season due to a series of severe snowstorms. It was reported that the service has had an impact on trip making. The statistics captured from the evaluation were:

50% of users call to verify that their planned route is feasible;

about 30% of callers use the information to choose between two or more alternative routes;

15% of users have changed their usual route, and 14% have changed their departure times, in response to information about congestion;

upon learning of a possible trip delay, about 6% of users have called to let others know they will arrive later than anticipated;

very few have changed modes or cancelled their trips;

about 2/3 of users list anxiety-reduction as a benefit from using the system;

about 50% of users indicated that the information lets them avoid traffic problems, save travel time, or arrive on time at their destination; and

 only 7% of users believe they don’t receive any benefit from calling Smart Traveler.
The results above indicate that the service can help travelers much in choosing travel routes. Proper route selections for each traveler result in proper distribution of traffics through the network, which means that the roads are utilized efficiently.

11.3.3 Congestion Pricing
The vital principle of congestion pricing is that during the peak periods of demand for a particular roadway where the highest social costs are incurred, a congestion fee is imposed to users. Congestion pricing is a market-based strategy designed to encourage a shift of peak period trips to off-peak periods or to other routes away from congested areas. Congestion pricing also encourages the use of transit and high occupancy vehicles. Trip chaining, foregone trips, changes in activity sequencing, changes in trip destinations, and changes in trip frequencies are other user responses to congestion pricing. Long-term behavioral changes would involve changes in residential and/or workplace locations to avoid the congestion price.

Various estimates for the social costs incurred during non-peak versus peak travel have been made. A research has indicated that the non-peak period social cost of vehicle travel is 3.7 cents per vehicle-mile, and that the peak period social cost of vehicle travel is 13.9 cents per vehicle-mile (Tellis and Khisty, 1995).

11.3.4 HOV Strategies
Provision of HOV lanes are useful, but they are not utilized only for high occupancy vehicles, but considered for the use of other vehicles such as bus or carpool vehicles recently. In Southern California, the bus on an exclusive HOV lane was viewed as a successful policy. After some time, the facility was opened to vanpools and car pools as well. In Houston, Texas, it was proposed that transit money mixed with highway money be utilized to build an extensive HOV system. The last major interstate system construction dollars to be spent in the San Francisco Bay Area is building an HOV facility extending northeast for 12 miles. Coupled with the HOV bypass on the Bay Bridge approach and the metering lights that control the flow on the bridge itself, it is expected to give a substantial time advantage to bus riders when this HOV is completed. In Southeastern Virginia, during peak traffic hours, HOV lanes carry nearly 12,000 passengers per weekday, taking as many as 12,000 vehicles out of the regular lanes, and rideshares save up to $2,000 per year in gas, maintenance, insurance and other commuting costs. The area's HOV-2 lanes can move as many passengers as four freeway lanes at full capacity.

A two reversible HOV lanes in the median of Interstate highway in San Diego, California was opened to a limited number of single drivers who purchased monthly “ExpressPass” permits for $70. Prior to the initiation of this project, use of the HOV-2 facility was limited to carpools with two or more passengers, motorcycles and emergency vehicles. With the advent of this pilot project proposed by the San Diego Association of Governments, carpools and the authorized vehicles continue to ride free, while solo-permit-holding motorists are allowed to take the HOV-2 facility. This congestion pricing results in travel time savings for ExpressPass users up to 10-20 minutes per trip. The HOV traffic with congestion pricing has increased by 15 percent, and the HOV violation rates have dropped from 14 percent to 2 percent. The drop in the HOV lane violation rate is attributable to increased police enforcement.
A fully automated dynamic pricing pilot project on that roadway called “FasTrak” began on March 1998. The system deducts pre-trip fees from pre-established accounts instead of charging a flat monthly fee. To accommodate the switch to dynamic pricing, monthly ExpressPass permits were replaced by window-mounted transponders, which allow for flexible charges depending on the degree of congestion. Fees are assessed using overhead readers and vary depending on the real-time congestion levels. To respond to those drivers shifting to public modes, an express bus service has been introduced as a part of the congestion management scheme.
The 10-mile project consisting of four express lanes constructed in the median of an eight-lane freeway in Orange County, California, is the first implementation of value pricing using electronic various toll device throughout the United States. Tolls range from $0.60 to $2.95, with vehicles having 3 or more paying a half-toll. Only vehicles equipped with transponders are allowed to enter into the Express Lanes. Since the opening of the Express Lanes, daily traffic volume on the toll gate has grown steadily and peak period delays on the toll-free roadways have dropped from an average of 30 to 40 minutes down to 5 to 10 minutes.
In January 1998, the Texas DOT launched a congestion pricing project on an existing 13-mile HOV lane of Interstate highway. The project “QuickRide” allows a limited number of HOV-2 carpools to enter the reversible HOV-3 lane during the peak-travel periods. During this time period, a participating vehicle with 2 persons pays a $2.00 per trip while a vehicle with 3 or more continues to travel free. Single-occupant vehicles are prohibited from using the HOV lane. Since the HOV project’s opening, about 500 transponders have been issued, with average daily trips ranging from 100 to 150 over the first 45 days.
Not every HOV is greeted with joy, however. Many have not attracted buses or carpools. In many cases, the enforcement of HOV occupancy rules has become infeasible. A study represented that carpool lanes in the San Francisco Bay Area have saved little time. Specifically, 54 carpool lanes in the Bay Areas were found that 33 of them did not reduce commuting times. Sixteen saved 10 minutes or less, and only six saved more than 10 minutes. Despite very expensive penalty, $271, there were a large number of cheating of one-occupant cars.

11.3.5 Progressive Traffic Signals and Others
Since progressive traffic signal systems have been introduced in the early 1960s, several benefits have been reported, including travel time, travel speed, vehicle stops, delays, and so on. A project regarding traffic signal system in Wichita Falls, Texas, reported a 16% reduction in stops, a 31 % reduction in vehicle delay, an 8.5% reduction in accidents, and an increase in speeds of over 50%. The performance of the computerized system was compared to the traditional simple system.(refer to )

Benefits of the Progressive Signal System in Wichita Falls, USA

Measure of Effectiveness

Degree of the Change

Travel time

Decrease 8% -15 %

Travel speed

Increase 14% - 22%

Vehicle stops

Decrease 0% - 35%

Delay

Decrease 17% - 37%

Fuel Consumption

Decrease 6%-12%

Source: US DOT, Traffic Signal System, 1999
The Automated Traffic Surveillance and Control (ATSAC) and the Fuel-Efficient Traffic Signal Management (FETSIM) programs in California showed benefit/cost ratios of 9.8:1 and 5.8:1, respectively. ATSAC system resulted in 13% reduction in travel time, 35% reduction in vehicle stops, 14% increase in average speed, 20% decrease in intersection delays. A Traffic Light Synchronization (TLS) system has been installed in a closed-loop signal system with hardware interconnection. An analysis for TLS system showed a benefit/cost ratio of 6.2:1. The impact of the system in on the network of a city in Texas is shown in the .

Benefits of the TLS System in a City in Texas, USA

Measure of Effectiveness

Degree of the Change

Travel time

- 13.8 %

Travel speed

22.2 %

Vehicle stops

- 0.3 %

Delay

- 37.1 %

Fuel Consumption

- 5.5 %

CO Emissions

- 12.6 %

HC Emissions

- 9.8 %

NOx Emissions

- 4.2 %

Source: US DOT, Traffic Signal System, 1999
The SCATS adaptive signal control in the FAST-TRAC program in the Detroit area has been fairly effective in eliminating accidents as a result of the installation of a traffic management system and related improvement to intersection geometric and signal phasing. In Detroit, injury accidents and injuries decreased 6%, 27%, respectively. In particular, serious injuries decreased 100% during a specific period, left turn accidents during peak hours decreased 89%, speed in peak time increased 19% and intersection delay decreased by up to 30%.
11. 4 Case Study 2: Electronic Road Pricing (ERP) in Singapore

Background of the ERP in Singapore

Singapore introduced a manual road pricing system called the Area Licensing Scheme (ALS) in 1975. Under the ALS, an area encompassing the most congested parts of the city was termed the Restricted Zone (RZ). During the day on weekdays and half-day on Saturday, vehicles wishing to enter the RZ needed to purchase and display an area license. Vehicles were free to move around within the RZ or leave it. Violators got a notice to pay a fine for entering the RZ without a valid license. In the mid-1990s, the same concept was extended to 3 expressways during the morning peak hours with separate licenses. This system for expressways was called the Road Pricing Scheme (RPS).
The ALS and RPS, however, were both labor-intensive in that they required many people for the sale of the licenses and the enforcement of violators.

Developing to Electronic Road Pricing (ERP) System

After much debate and analysis, a more active electronic road pricing (ERP) system which requires the use of a smartcard for payments was developed for about 2 years and successfully implemented in April 1998. The ERP system replaced the coupon-based Road Pricing Scheme (RPS) on the East Coast Parkway in April 1998 and the Central Expressway in August 1998. In September 1998, Phase I of ERP implementation was complemented with the start of ERP on the Pan-Island Expressway and the automation of the Area Licensing Scheme for the Restricted Zone. In all, 33 gantries were commissioned. The massive 10-month exercise to install the ERP In-vehicle Unit (IU) in nearly 700,000 vehicles came to a close in July 1998. Almost all vehicle owners took advantage of the free IU installation exercise with a participation of about 97% of all registered vehicles.

Configuration of the ERP

The ERP system consists of three main components: the In-vehicle unit (IU), the gantry, and the central computer system. The IU is an electronic device installed in a private vehicle that accepts a stored value CashCard. The IU deducts the appropriate ERP charges from the CashCard each time the vehicle passes through an ERP gantry. Registration plates of vehicles making illegal entries, such as those without an In-vehicle unit, without a CashCard, or with an insufficient balance on the CashCard, are to be photographed by the gantry cameras, for subsequent enforcement action.