Salt Lake City, Utah, United States
Understanding Connected and Automated Vehicles’ Impacts on Utah Transportation Planning
Summary Information
|
Utah DOT developed a project based on the initial 2016 deployment of a full Dedicated Short-Range Communications (DSRC) corridor that supported transit signal priority (TSP) controls to leverage connected and automated vehicle (CAV) technology. The deployment site is located along Redmond Road, an 11-mile urban corridor with 30 signalized intersections located in Salt Lake City. Onboard communication devices were installed on transit vehicles to support the TSP system. The project aimed to collect bus data along the DSRC corridor to evaluate the efficiency of the technology's investment and perform a benefit-cost (B/C) analysis. Moreover, this project integrated adaptive traffic and signal coordination controls into the existing system to optimize signal timing at the intersection level and offset at the corridor level. A microscopic simulation environment based on the DSRC corridor was developed to evaluate the potential effects of the proposed signal control system. |
Methodology
Related bus data from UDOT and Utah Transit Authority (UTA) for the deployment site was first collected to conduct the B/C analysis. Travel time savings served as the main metric used to evaluate the benefits. The cost captures the lifecycle costs associated with roadside equipment (RSE) deployment. Future benefits were estimated for a proposed system that integrates adaptive traffic signal control at the intersection level and signal coordination control at the corridor level using a simulation-based evaluation. The benefit-cost analysis was conducted using simulation experiments with different CAV market penetration rates (5, 10, 15, 20, 25, 50, 75, and 100 percent) during a 10-year timeframe from 2018 to 2027.
Findings
Table 1 presents the B/C analysis results under different market penetration rates. When the market penetration rate is equal to or larger than 10 percent, the deployment for supporting the adaptive coordination control is found to be an efficient investment with a B/C ratio larger than 1.0 and a net benefit between $1 million and $16 million.
Table 1: Benefit/Cost Analysis for CAV Simulation at Different Market Penetration Rates
|
Market Penetration Rate |
Benefits ($) |
Costs ($) |
B/C Ratio |
Net Benefit ($) |
|
100% |
17,329,961 |
1,180,300 |
14.68 |
16,149,661 |
|
75% |
17,292,035 |
1,180,300 |
14.65 |
16,111,735 |
|
50% |
17,028,466 |
1,180,300 |
14.43 |
15,848,166 |
|
25% |
16,806,060 |
1,180,300 |
14.24 |
15,625,760 |
|
20% |
11,256,311 |
1,180,300 |
9.54 |
10,076,011 |
|
15% |
7,137,071 |
1,180,300 |
6.05 |
5,956,771 |
|
10% |
2,605,413 |
1,180,300 |
2.21 |
1,425,113 |
|
5% |
1,041,283 |
1,180,300 |
0.88 |
-139,017 |
Note that the market penetration rate may not remain stable within the ten year timeframe due to various factors such as technological improvements. As a result, the project also estimated the B/C ratio at increasing penetration rates (5 percent from 2018 to 2023, 10 percent in 2025, and 15 percent from 2026 to 2027). The B/C ratio under these estimations is 2.25 and the net benefit is $1,487,717.
