Project ID
|
Jurisdiction
|
Construction cost
(thousand $)
|
2090001
|
Arlington
|
14,000
|
2090002
|
Arlington
|
18,000
|
2090003
|
Arlington
|
11,000
|
2090005
|
Arlington
|
18,000
|
The lower and higher values of maintenance cost and other lifecycle costs over the project life are estimated for each project using the input data and input parameters. For example, Table 9 shows the undiscounted and discounted values of the life-cycle cost for the sample of projects shown in Table 8.
Table 9. Undiscounted and Discounted Life-Cycle Costs for the NOVA District Projects
Project ID
|
Undiscounted Life-Cycle Cost
|
Discounted Life-Cycle Cost
|
Low
|
High
|
Low
|
High
|
2090001
|
$2,333,333
|
$9,800,000
|
$1,355,325
|
$5,820,207
|
2090002
|
$3,000,000
|
$12,600,000
|
$1,742,560
|
$7,483,123
|
2090003
|
$1,833,333
|
$7,700,000
|
$1,064,898
|
$4,573,020
|
2090005
|
$3,000,000
|
$12,600,000
|
$1,742,560
|
$7,483,123
|
The low and high estimates of the present value of the capital cost are developed for each project. The range associated with the present value of the project capital costs depends on the range of construction time associated with that project. Table 10 shows lower and higher estimates of an undiscounted combination of capital, maintenance and other life-cycle cost for the sample of projects shown in Table 8.
Table 10. Total Cost Estimates for the NOVA District Projects
Project ID |
Capital + maintenance +other life-cycle costs
|
Low
|
High
|
2090001
|
$16,683,333
|
$24,976,000
|
2090002
|
$21,450,000
|
$32,112,000
|
2090003
|
$13,108,333
|
$19,624,000
|
2090005
|
$21,450,000
|
$32,112,000
|
Overall, the cost estimation model can provide a systematic approach for incorporating life-cycle cost estimates to the cost-benefit analysis of road improvements and can be used in future research.
RESULTS
Overview
A case study of the Northern Virginia district demonstrates an application of above methodology and provides results in several sections: crashes avoided, travel time savings, reduced vehicle operating costs, emissions avoided, and heavy truck traffic.
There are 53 total candidate projects for Northern Virginia district with costs ranging from $2 million to $130 million. The input data collected for this district is shown in Table 11. Each project is labeled by its ID number. The input parameters shown in the table are road type, length of the project, 2004 volume-to-capacity ratio during peak period, 2004 AADT, crash rate, number of heavy trucks per day and total cost of the project.
In interpreting the results, it is important to note some common assumptions on which results are based. For example, the lifetime of each project is considered to be 25 years. It is assumed that project implementation will cause reduction in volume-to-capacity ratio in a uniform range between 10% and 50%. Roadway length influenced by the project, l is considered to be five times the length of the project. The proportion of traffic that occurs during the peak period, is fixed at 25% of AADT. These values can be changed as required in the prototype prioritization software.
Table 11. Northern Virginia Input Data
ID
|
Road
type
|
Project length
(miles)
|
2004
V/C ratio
|
2004
AADT
|
Crashes per 100 million VMT
|
# Heavy trucks per day
|
Total Cost
(thousand $)
|
2090001
|
U6D
|
0.91
|
1.24
|
76,213
|
88.92
|
1,451
|
14,000
|
2090002
|
U6D
|
1.37
|
1.64
|
70,000
|
101.48
|
1,400
|
18,000
|
2090003
|
U6D
|
0.40
|
0.6
|
27,220
|
541.37
|
272
|
11,000
|
2090005
|
U6D
|
1.08
|
1.22
|
32,073
|
255.54
|
321
|
18,000
|
2090007
|
U6D
|
0.64
|
1.41
|
66,326
|
313.1
|
663
|
7,000
|
2090009
|
U6D
|
0.47
|
1.1
|
74,976
|
135.19
|
1,500
|
10,000
|
2090011
|
U6D
|
0.83
|
0.94
|
34,878
|
703.35
|
1,046
|
13,000
|
2090012
|
U6D
|
0.22
|
0.8
|
29,675
|
578
|
890
|
4,000
|
2090013
|
U4
|
0.40
|
0.98
|
14,564
|
232.81
|
146
|
5,000
|
2090014
|
U4
|
1.99
|
0.62
|
16,225
|
385.66
|
487
|
20,000
|
2090015
|
U4D
|
0.07
|
1.66
|
26,228
|
652.8
|
525
|
2,000
|
2090016
|
U4D
|
1.72
|
1.04
|
33,500
|
808.07
|
1,005
|
16,400
|
2090018
|
U4D
|
0.23
|
0.96
|
33,500
|
481.12
|
1,005
|
5,000
|
2090019
|
U4D
|
1.02
|
1.15
|
14,000
|
391.28
|
467
|
14,000
|
2090020
|
U4D
|
1.17
|
0.72
|
15,355
|
468.61
|
461
|
12,000
|
2090025
|
U6D
|
8.80
|
1.56
|
61,082
|
184.73
|
1,222
|
130,000
|
2090026
|
U8D
|
2.23
|
1.22
|
68,460
|
532.61
|
3,423
|
54,000
|
2090027
|
U6D
|
1.92
|
1.04
|
36,840
|
458
|
1,105
|
20,000
|
2090028
|
U8D
|
0.52
|
0.89
|
50,694
|
574.67
|
2,535
|
10,000
|
2090029
|
U6D
|
1.38
|
1.33
|
50,655
|
585.41
|
2,533
|
22,000
|
2090030
|
U6D
|
2.67
|
1.75
|
60,697
|
286.9
|
3,035
|
28,500
|
2090032
|
R4D
|
0.70
|
0.57
|
15,451
|
57
|
310
|
12,000
|
2090033
|
U6D
|
5.53
|
1.12
|
39,181
|
245.13
|
1,567
|
65,000
|
2090036
|
U8D
|
0.82
|
2.05
|
69,679
|
184.54
|
2,090
|
14,000
|
2090037
|
U6D
|
3.27
|
1.15
|
58,615
|
282.93
|
1,758
|
40,000
|
2090040
|
U6D
|
12.57
|
1.2
|
37,828
|
182.89
|
1,135
|
130,000
|
2090045
|
U6D
|
3.09
|
2.02
|
61,000
|
198.29
|
1,725
|
40,000
|
2090046
|
U6D
|
0.87
|
1.04
|
53,000
|
294.85
|
530
|
15,000
|
2090047
|
U8D
|
0.87
|
1.6
|
77,094
|
552.82
|
771
|
15,000
|
2090048
|
U6D
|
4.96
|
1.4
|
47,541
|
243.37
|
475
|
60,000
|
2090049
|
U4
|
0.81
|
1.23
|
30,507
|
84.22
|
305
|
8,000
|
2090053
|
U6D
|
7.27
|
1.59
|
54,000
|
427.72
|
1,620
|
90,000
|
2090055
|
U4
|
0.50
|
1.28
|
35,000
|
300
|
700
|
4,000
|
2090056
|
U6D
|
2.36
|
0.98
|
36,222
|
555.45
|
1,811
|
30,000
|
2090057
|
U4D
|
2.35
|
1.8
|
25,605
|
190.04
|
768
|
23,000
|
2090100
|
U6D
|
5.05
|
0.97
|
39,116
|
305.17
|
391
|
65,000
|
2090069
|
U6D
|
12.00
|
1.23
|
36,500
|
457
|
933
|
32,600
|
2090070
|
U6D
|
8.00
|
1.23
|
36,500
|
227
|
2,190
|
80,000
|
2090072
|
R4D
|
4.20
|
0.46
|
15,670
|
127.9
|
940
|
30,000
|
2090073
|
U6D
|
3.50
|
1.32
|
29,112
|
297.75
|
2,329
|
28,000
|
2090074
|
U6D
|
2.13
|
1.64
|
50,000
|
303.64
|
2,500
|
40,000
|
2090076
|
U6D
|
0.80
|
1.32
|
59,000
|
513
|
4,720
|
125,000
|
2090077
|
U4D
|
0.64
|
0.26
|
7,173
|
855
|
645
|
8,000
|
2090083
|
U6D
|
1.78
|
1.32
|
33,573
|
446.48
|
2,016
|
28,200
|
2090085
|
U6D
|
1.28
|
0.32
|
5,550
|
185
|
500
|
12,000
|
2090062
|
R6D
|
2.38
|
1.09
|
48,000
|
78
|
2,400
|
50,000
|
2090XXX
|
R6D
|
2.87
|
0.83
|
62,000
|
279
|
3,100
|
50,000
|
2090101
|
R6D
|
5.29
|
0.58
|
39,278
|
117.9
|
3,142
|
130,000
|
2090102
|
U8D
|
5.61
|
1.07
|
61,004
|
137.99
|
1,220
|
100,000
|
N1
|
R4D
|
4.25
|
1.64
|
50,000
|
156.74
|
1,500
|
115,000
|
N2
|
R4D
|
5.60
|
1.62
|
85,107
|
156.74
|
851
|
60,000
|
N3
|
R4D
|
4.00
|
1.54
|
95,182
|
156.74
|
3,807
|
7,000
|
N4
|
R4D
|
5.30
|
1.54
|
95,182
|
156.74
|
3,807
|
50,000
|
Crashes Avoided
Lower, higher and median values of benefit-cost ratio due to crashes avoided are calculated. Figure 1 provides graphical presentation of the results from the analysis of the benefits of crashes avoided. Each horizontal bar in the graph starts at the lower value of benefit-cost ratio and ends at the higher value. The vertical mark on each bar represents median estimate. The bars are labeled by their associated project ID. The graph highlights which projects have the highest benefit-cost ratio, where the monetized benefits are based upon the anticipated crashes avoided.
Figure 2 is a comparison of the number of crashes to the benefit-cost ratio. The projects located toward the top right of the figure have more crashes per year and higher vehicle miles traveled. The size of the bubble corresponds to the median estimate of benefit-cost ratio. In general, the projects in the lower left tend to have smaller benefit-cost ratios as compared to the projects located in the upper right.
Figure 3 shows the results of the cost-effectiveness calculation of crashes avoided per dollar. This graph is related to Figure 1 in that the ordering of the candidate projects is the same.
Figure 1. Benefit-Cost Ratio for the Crashes Avoided
Figure 2. Comparison of Number of Crashes to the Benefit-Cost Ratio
Figure 3. Cost Effectiveness Analysis for the Crashes Avoided
Table 12 provides the top five candidate projects using two different prioritization rules: the benefit-cost ratios for crash avoidance, and the current crash rate based scoring rule associated with safety goal used by VDOT. The project 2090016 is the only common project among the top five projects generated by both the prioritization rules.
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