The USDOT in partnership with Transport Canada, AASHTO and in cooperation with other nationwide stakeholders, conducted analyses leading to a preliminary general concept of a national Connected Vehicle (CV) field infrastructure footprint. The footprint includes a general description for a proposed national deployment of vehicle-to-infrastructure (V2I) technology including, applications, communications and deployment locations. The purpose of the National CV Field Infrastructure Footprint Analysis is to provide a vision for a fully deployed infrastructure footprint, to identify the activities and project timelines needed to achieve that footprint, and to estimate costs associated with the deployment.

As with traditional traffic operations equipment any DSRC site infrastructure for V2I deployment will require regular maintenance and incur ongoing operational costs. The following outlines the estimated costs for operation and maintenance of the hardware systems to ensure that the deployment remains functional over time.

Field Infrastructure Operations Costs

The costs associated with operation of this equipment include standard considerations for power and communication (in the case of leased lines), as well as the additional cost to existing Operations Centers for additional hardware and personnel to monitor system performance.

Power consumption of the communication and data processing equipment at the intersection is not expected to require new or upgraded infrastructure, but will draw more energy per site than traditional traffic controller equipment. A DSRC radio is expected to have power consumption similar to a typical home Wi-Fi router (10 Watts (W) per hour). Additional equipment required for operating a DSRC unit at a local intersection is not expected to draw more power than a typical computer workstation (100 W per hour). At an average price of $0.10 per kilowatt-hour (average price in North America) and operating for 24 hours per day, seven days per week, the anticipated annual power cost per site is $97.

The ongoing costs associated with maintenance of backhaul networks deployed for ITS should also be noted. The cost of this maintenance, as discussed in the NCHRP 03-101 report, will vary between two and five percent of the original hardware and labor costs, but are not included in this report because these costs will be incurred independent of any national connected vehicle field infrastructure deployment.

Field Infrastructure Maintenance Costs

Regular maintenance costs are expected to be comparable to those required for maintaining similar existing equipment such as traffic signals and the signal controller. As identified in the NCHRP 03-101 report, the annual maintenance costs are anticipated to be between 2 to 5 percent of the hardware and installation costs per year. Routine maintenance includes such items as realigning the antennas, rebooting hardware, checking the system to confirm operation status and other typical checks. This maintenance is likely done by visiting each site two to four times per year. The assumed hardware and installation costs per device are $10,677, so the annual cost for maintenance, assuming a 5 percent per year per device cost, is approximately $533. (Note: The reader may notice that the total maintenance cost is the same as the average deployment cost; this is not an error, but based on the estimated 5 percent (.05) of the total cost being aggregated over 20 years.)

As with most technologies, there will also likely be an annual license or maintenance fee for the device for support from the manufacturer. This fee is intended to cover the costs of developing and distributing firmware updates that improve functionality and security of the device (similar to service patches and updates with commercial computer operating systems). The annual maintenance fees for these devices currently vary significantly by manufacturer and range from a fixed cost per test bed site to an annual cost that is set per device. For planning purposes, an estimate of $200 per device per year is being used.

Finally, assuming that the SCMS will be a privately operated program, all agencies should plan on recurring costs to keep the security credentials on the system up to date. Because the business models for the SCMS are evolving at this point, an estimate of $50 per year per device is assumed.

Field Infrastructure Replacement Costs

As with traditional traffic operations equipment, the connected vehicle infrastructure will need to be replaced as it reaches the end of its lifecycle. Because these are new technologies, their anticipated life span is unproven. DSRC radios share similar components to home Wi-Fi routers which can last anywhere from one year to ten or more years before needing replacement, although not subject to an outdoor environment. Cisco routers and switches, based on industry experience, have an expected lifespan of seven to eight years. Traffic signal controllers, if undisturbed (not physically damaged within the cabinet or by a power surge), often remain operational for ten to twenty years or longer.
For the estimated lifecycle and replacement cost, it is assumed based on stakeholder input that the hardware deployed for connected vehicles will have a life-span of ten years. The operational lifespan of the RSUs is not, however, solely a function of the hardware. It is expected that the RSU software will be updated on a regular basis to assure that the devices have the latest security and application updates. It is also likely that the operational software lifetime, even with regular updates, is less than that of the hardware—potentially as low as five years.
The cost to replace the DSRC RSUs, assuming a direct replacement of the complete hardware/software unit, should be limited to the unit itself and original installation costs. Other deployment costs for design, inspection, and so forth would not be incurred for a direct replacement. Therefore, the anticipated costs for replacement are $10,677 per site every five to ten years.

Table 1 -Estimated Annual DSRC Site Operations, Maintenance and Replacement Costs (Source: USDOT/AASHTO 2014)

This report, dated June 2014, includes many more details of connected vehicle system costs. These findings along with the costs provide a valuable resource to those considering the implementation of connected vehicle infrastructure.