Rapid deployment of DSRC for connected vehicles can save thousands of lives, regardless of whether a later transition to C-V2X proves advantageous.
A comparison of Dedicated Short-Range Communications (DSRC) vs. Cellular Vehicle to all (C-V2X) as a radio media for vehicle to vehicle safety applications.
Made Public Date
07/23/2018

13

Nationwide
United States
Identifier
2018-01278
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DSRC vs. Waiting for C-V2V: Lost Benefits and a Proposed Dual-Mode Solution

Summary Information

This paper estimated the safety benefits of moving forward with a nationwide deployment of DSRC-based solutions to connected vehicle applications, as they are ready today, while continuing development of Cellular Vehicle-to-Everything (C-V2X) alternatives, and then implementing a "dual-mode transition" to C-V2X if this technology proves to be a better solution in the future.

DSRC is a variant of Wi-Fi that has been optimized for mobile environments and direct communications between devices, without an intermediary access point. It is defined in the IEEE 802.11p standard.

C-V2X uses cellular direct device-to-device communications to create a wide-area network without the need for a cellular base station. C-V2X can support high vehicle high speeds (up to 250 kilometers per hour) and high density (thousands of nodes). The current standard for C-V2X was completed in September 2016.

METHODOLOGY

The analysis estimated the potential benefits of moving ahead with DSRC connected vehicle solutions today followed by a "dual-mode transition" period where both DSRC and C-V2X are deployed. These benefits were then compared to the benefits lost if required to wait until C-V2X has matured or been proven better than DSRC before connected vehicle applications can be deployed.

Data from NHTSA web pages (NHTSA's NPRM for V2V Communications) and reports from (Preliminary Regulatory Impact Analysis, FMVSS No. 150, Vehicle-to-Vehicle Communication Technology for Light Vehicles) were used in the analysis.

FINDINGS

 

The baseline scenario for the analysis assumed that a decision to wait for C-V2X would result in a delay of 5 years (3-year and 7-year delays are also analyzed). For the 5-year baseline scenario, the more rapid-deployment enabled by DSRC is estimated to save more than 3,800 lives.

The table below excerpted from the source report shows the additional lives saved through earlier deployment of V2V safety applications. Note that the benefits would be even greater if it was determined that there is no reason to transition to another technology, such as C-V2X.

 

 

3 Year Delay

5 Year Delay

7 Year Delay

 

Low

High

Low

High

Low

High

Lives Saved

2,200

3,100

3,800

5,200

5,400

7,400

Lives saved are not the only benefits provided by V2V safety applications. There are also fewer injuries and less property damage. The table below excerpted from the source report shows the total additional monetized benefits gained through earlier deployment.

 

 

3 Year Delay

5 Year Delay

7 Year Delay

 

Low

High

Low

High

Low

High

3% Discount Rate

$85.6 B

$115 B

$145 B

$195 B

$203 B

$273 B

7% Discount Rate

$53.9 B

$72.2 B

$86.8 B

$116 B

$116 B

$155 B

The "dual-mode transition" scenario analysis used a scenario where the nation would move forward with DSRC-based deployment, but would transition through a dual-mode deployment for several years before converting to purely C-V2X, should the latter prove superior in some way. The results below indicate that even with the additional costs of dual-mode systems, this "dual-mode transition" approach with a transition period provides benefits from earlier deployment that would significantly outweigh the additional cost.

The table below shows the total net benefits of a "dual-mode transition" scenario in 2014 dollars (2014 $).

 

 

3 Year Delay

5 Year Delay

7 Year Delay

  Low High Low High Low High
3% Discount Rate $539 B $759 B $535 B $753 B $534 B $751 B
7% Discount Rate $210 B $302 B $211 B $302 B $212 B $311 B

The table below shows the incremental net benefits for a "dual-mode transition" scenario vs. the "wait for C-V2X" scenario. Again, the net benefits, considering the higher costs of dual-mode systems, are positive under all scenarios.

 

 

3 Year Delay

5 Year Delay

7 Year Delay

  Low High Low High Low High
3% Discount Rate $66.0 B $95.4 B $124 B $174 B $181 B $251 B
7% Discount Rate $53.9 B $61.7 B $69.8 B $99.0 B $116 B $136 B

Overall, the report finds that it would be beneficial to move forward with a DSRC-based deployment, saving thousands of additional lives, regardless of whether a later transition to C-V2X proves advantageous.