Prevent the need for channel switching (a safety hazard) by designing CV communications to include dual radios in each vehicle

Success Stories from the USDOT’s Connected Vehicle Pilot Program

Wyoming; United States

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Lesson Learned

In the area of communications, the CV Pilot sites are using established standards wherever possible, but in many cases, they are trying out standards in the field for the first time, or are implementing messages for which no national or international standards have yet been established.
A key component of connected vehicle communication is Dedicated Short Range Communication (DSRC) in the 5.9 GHz band. Within this band are several channels. Channel 172 is the primary channel, carrying safety-related information and WAVE Service Announcements (WSAs) that advertise the availability of other information and services on other channels. The IEEE 1609.4 standard addresses multi-channel operation for Wireless Access in Vehicular Environments (WAVE), and as such is the "official" set of rules for wireless messages by the CV Pilot sites.

The New York and Tampa teams plan to use dual radios in each vehicle: one to listen to channel 172 and the other to listen to other channels for supplementary information such as Traveler Information Messages. The Wyoming team, on the other hand, originally planned to use a single radio, listening to channel 172 most of the time, but switching to other channels to listen for other messages. Such a channel-switching plan is consistent with IEEE 1609.4 specifications. However, the 1609.4 committee and several manufacturers who are looking ahead to implementation of DSRC required by a ruling from the National Highway Traffic Safety Administration (NHTSA), maintain strongly that it is not safe to switch away from Channel 172, because a safety-critical message on that channel might be missed.

The Wyoming team has agreed to re-design its communications design to include dual radios. However, the discovery that a single channel-switching radio is technically compliant to the 1609.4 standard is a major loophole in the standard that must be addressed and corrected by the 1609.4 committee.

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Connected Vehicle Pilot Deployment Program: Success Stories

Author: Glassco, Rick; James O'Hara; Barbara Staples; Kathy Thompson; and Peiwei Wang

Published By: USDOT Office of the Secretary for Research and Deployment

Source Date: 11/01/2017

URL: https://www.its.dot.gov/pilots/success_lessonslearned.htm

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Kathy Thompson


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Lessons From This Source

Allow for increased coordination with the Interdepartmental Radio Advisory Committee (IRAC) early on in the DSRC licensing process to help reduce what is traditionally a very lengthy process.

Connected Vehicle Pilot Deployment Program yields program management best practices for integrating and testing large disparate systems.

Connected vehicles should rely on more than one data feed to determine accurate location and speed

Consider installing additional vehicle detection equipment if it is determined that there is not sufficient market penetration for CV traffic signal control applications to work at their full potential

Facing a gap in standards interpretation, the Tampa and New York City Connected Vehicle Pilot Sites worked together to harmonize message structure for pedestrian safety applications.

For pedestrian safety warning applications, opt to collect pedestrian location data from LIDAR sensors instead of pedestrian mobile devices that often have insufficient accuracy.

Incentivize participation in CV deployments through benefits such as toll discounts

Include technical, operations, and legal personnel in stakeholder meetings to address the requirements of the CV deployment and ensure that participants' privacy is being maintained

Incorporate standardized over-the-air update procedures to permit efficient firmware updates for connected vehicle devices.

Obtain working prototypes of CV applications from the USDOT’s Open Source Application Data Portal (OSADP) to prevent time spent doing duplicative software development

Prevent the need for channel switching (a safety hazard) by designing CV communications to include dual radios in each vehicle

Publish all CV planning documentation to serve as an example for other early deployers to follow

The Tampa Connected Vehicle Pilot Program investigates damage to roadside units (RSUs) near lightning strikes and improves transient surge immunity by verifying nearby support structures are properly grounded.

The USDOT’s three Connected Vehicle Pilots successfully demonstrate cross-site over-the-air interoperability among six participating vendors.

Use local student mechanics where possible to perform CV equipment installations to provide students with required trainee experience and to contain costs

Use on-board connected vehicle (CV) technology and SPaT / MAP infrastructure messages to prevent wrong way entries on reversible express lanes.

When installing antennas on streetcars to support wireless connected vehicle applications, verify that radio performance is not compromised by interference from high-voltage power lines.




United States

Systems Engineering

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Lesson ID: 2017-00795