Vehicle technologies are advancing faster than ever and there is a growing need to better understand how and when the traditional infrastructure will be impacted. Some agencies are starting to question the value of maintaining signs, roadside hardware, and other key physical highway infrastructure (because they might not be needed in the future). While there may be a day in the distant future when vehicles can navigate without any physical guidance, until then, physical guidance has to serve both the human driver and the machine driver. This physical guidance is mostly provided by traffic control devices. Traffic control devices have a long history of research, development, and testing to ensure that human road users can navigate anywhere within the US without having to relearn traffic codes. The MUTCD has evolved over the last 80 years to define a system in which agencies uniformly apply traffic control devices. All of the research, testing, and application guidance provided through the MUTCD has focused exclusively on the human driver. There is a growing and urgent need to assess how traffic control device designs and applications can be modified to accommodate both the human driver and the machine driver.
For the past three years, the TRB Automated Vehicle Symposium has hosted breakout sessions focused on the highway infrastructure. These breakout sessions have been attended by a mix of representation from transportation agencies and the automotive industries. A recurring discussion at these meetings has been related to the need to reassess traffic control device design and application with machine driver concepts in mind. For the past two years, vehicle industry experts have reported examples from their real-world demonstrations of how the existing traffic control device designs and applications appear non-uniform from their perspective and could be improved. According to the available research, there are significant safety and mobility benefits to be gained from advanced vehicle technologies that are not likely to be achieved from other sources.
The overall objective of this research is to assess how elements of the physical highway infrastructure (with an emphasis on traffic control devices) can be designed, enhanced, and/or applied to meet the needs of both the human driver and the machine driver. The research team should work with AV system developers to understand their technologies and processes for handling traffic control devices, including traffic control devices within work zones. The research team should also engage vendors of traffic control device materials regarding potential enhancements and feasibility of new product development. Existing research and innovations in retroreflectivity and other characteristics in traffic control devices should be included. The deliverables should include a detailed assessment of the current challenges as seen from the AV system developers as well as the highway owners and operators, suggestions to overcome those challenges with specific examples, implementation suggestions, and a roadmap outlining additional research, analysis, and milestones.