Lessons Learned from the Design/Build/Test Phase of the USDOT’s Connected Vehicle Pilot Program.
Connected Vehicle Pilot Deployment Program Driving Towards Deployment: Lessons Learned from the Design/Build/Test Phase
In September of 2015, USDOT selected New York City Department of Transportation (NYCDOT), Wyoming Department of Transportation (WYDOT) and Tampa Hillsborough Expressway Authority (THEA) as the recipients of a combined $42 million in federal funding to implement a suite of connected vehicle applications and technologies tailored to meet their region’s unique transportation needs under the Connected Vehicle Pilot Deployment Program.
Following the award, each site spent 12 months preparing a comprehensive deployment concept to ensure rapid and efficient connected vehicle capability roll-out. The sites next completed a 24-month phase to design, build, and test these deployments of integrated wireless in-vehicle, mobile device, and roadside technologies. As of early 2019, the sites are entering a third phase of the deployment where the tested connected vehicle systems will become operational for a minimum 18-month period and will be monitored on a set of key performance measures.
Given the promising future of connected vehicle deployments and the growing early deployer community, experiences and insights across all stages of the Design/Build/Test Phase of the CV Pilots have been collected to serve as lessons learned and recommendations for future early deployer projects and efforts.
The following lessons outline any changes needed to prepare roadways and intersections for the installation of CV devices.
Consider the location of existing ITS and line of sight when selecting sites for the installation of RSUs
- Wherever feasible, CV equipment should be collocated at closed-circuit television (CCTV), dynamic message sign (DMS) or traffic signal locations sites to take advantage of the existing roadside infrastructure, power and communications equipment. RSU mounting locations should also be optimized to achieve clear line of sight free of radio frequency (RF) signal path interference from trees, bridges, overpasses and other structures.
In New York City, many signal poles and mast arms lay behind the building face line, therefore limiting the line-of-site. Field inventories identified 15% of the installations would require additional infrastructure changes (e.g. additional communications gear, new mast/luminaire arms, controller relocation) to place the RSU with adequate line-of-site.
Account for a slower rate of installation of RSUs than OBUs as they require dispatch crews
- For the New York City pilot, the RSU installations were performed by NYCDOT field crews at a rate of about two per day per crew, a slower rate than what the NYC team had anticipated. The installation consisted of installing the surge suppressor on the ethernet to the RSU, adding the PoE inserter, bolting on the RSU, installing the ethernet through the pole and mast arm to the bottom of the RSU – and finally powering up the units and letting the system configure and start operation.
Configuring the RSU is currently a manual process and prone to errors, however that process will eventually be automated and managed by the TMC so that it will be truly plug-and-play.
Have integration with the next generation internet standard at the TMC
- DSRC CV deployments utilize IPv6 messaging. Though IPv6 can coexist with IPv4, IPv6 is the best answer to sufficiently address speed, security, efficiency and operational ease desired for the operation of CV systems. During transition from IPv4 to IPv6, many of the Pilots’ network devices did not support IPv6. Some devices were able to apply simple firmware updates, but many others required the purchase of new hardware.
In summary, early deployers should be cognizant that the most recent version of the internet protocol is not offered on every network natively and that there may be lengths in the network where IPv6 access must be provided through tunneling or through a tunnel broker.
Apply and update standards conformance where appropriate
- Though there currently is no USDOT RSU/OBU standard, all RSUs and OBUs used for deployment should conform to USDOT specifications as closely as possible wherever they exist; additionally, all messages should conform to the latest versions of SCMS, SAE J2735, SAE 2945/x, IEEE 802.11p, IEEE 1609.x, NTCIP 1202, NTCIP 1103, ISO 19091 and related standards. Vendors are expected to work with the deployer agency to determine the appropriate version for each standard/device specification that has been accepted for general use.
Upgrade needed firmware and software on Advanced Transportation Controllers (ATCs)
- The RSU shall maintain a system clock based on timing information from a local positioning system. GPS typically serves as the primary time source and the Network Time Protocol (NTP) server is intended to be available as a secondary, backup time source in the event that the RSU loses GPS. To support this, it is necessary that the firmware of the ATCs be upgraded to provide SPaT and time clock information directly to the RSU.
Update intersection geometry for accurate MAP message generation
- The OBUs compare GPS location readings on the vehicle against the MAP messages’ static intersection geometry data to determine a vehicle’s approach. As it is critical that the vehicle have an exact reference point within the intersection, agencies must ensure the MAP data is properly coded and that the Uper Hex code is validated for field testing.