February 28


The AASHTO SPaT Challenge

By Mike Spack

February 28, 2017

AASHTO, autonomous vehicle, driver assist, SPaT, V2I, V2V

Guest post by Jacob Rojer, EIT Spack Consulting

Autonomous vehicles and driver assist features have become increasingly popular in recent years. There are three main dimensions of automated vehicles: driving automation & driver assistance, vehicle to vehicle (V2V) connectivity, and vehicle to infrastructure (V2I) connectivity. I recently attended a North Central Institute of Transportation Engineers (NCITE) meeting where speakers from the Minnesota Department of Transportation (MnDOT) presented on V2I connectivity, but more specifically, the SPaT Challenge. Here’s a summary of what the presentation covered and my takeaways from it.

SPaT stands for Signal Phasing and Timing. The SPaT challenge is an initiative started by the American Association of State Highway and Transportation Officials, otherwise known as AASHTO. Here is AASHTOs description of the SPaT Challenge, “AASHTO is challenging the state and local public sector transportation infrastructure owners and operators to cooperate together to achieve deployment of DSRC infrastructure with SPaT, MAP, and RTCM broadcasts in at least one corridor or network (approximately 20 signalized intersections) in each of the 50 states by January 2020 (referred to as the “AASHTO SPAT Challenge”)” or in short “20 in 50 by 20”. To understand why this challenge is necessary, it’s important to know about the driving forces behind each of the three dimensions of automated vehicles and how they work together.

Driver Automation and Driver Assistance

The first and most common right now is the driver automation and driver assistance. The popularity of these features such as lane departure warning, adaptive cruise control, and self-parking features are market driven, as people want features in their vehicles to make driving easier and less of a hassle. These systems generally rely on sensors and cameras built into to the vehicle to monitor its surroundings. Another incentive for the car manufactures is that they aren’t relying on a third party to implement these features. However, these features aren’t currently utilizing their full potential without V2V and V2I.

Vehicle to Vehicle Connectivity (V2V)

The National Highway Traffic Safety Administration (NHTSA) has a mandate out that will require car manufactures to include dedicated short-range communication (DSRC) devices in new vehicles. Having a government mandate to implement V2V connectivity will greatly improve the capabilities of the autonomous and safety features in vehicles because instead of a vehicle being reactive to surrounding vehicles, they would preemptively be able to adjust by receiving information about what other vehicles are doing that might be outside the vehicles sensor or camera range.

Vehicle to Infrastructure Connectivity (V2I)

V2I connectivity does not have the market or a government mandate to facilitate its growth. This is why the SPaT Challenge has been issued. Before the SPaT Challenge, there was no incentive to develop and install the infrastructure because there are not any vehicles that would be able to use it. Conversely, vehicle manufactures weren’t developing a system to connect to infrastructure because there isn’t any infrastructure to connect to (Chicken, meet egg). The SPaT Challenge will hopefully provide the push to get the ball rolling for V2I connectivity. One useful application of V2I connectivity right now could be red light warnings in your vehicle (similar to current collision warnings in vehicles). This would be both a safety feature as well as allow for more economical driving (less fuel, less pollution, etc.).

All three dimensions are required to move to fully autonomous vehicles. Currently, driver automation & driver assistance is the most prevalent of the three dimensions but it is important to continue to develop V2V and V2I technology. Issuing the SPaT Challenge to work on V2I technology now will help orchestrate new developments for future applications and make sure V2I connectivity doesn’t fall too far behind the other dimensions of automated vehicles.

Unfortunately, the SPaT Challenge does not come with funding. But the efforts will be coordinated so agencies can learn from each other and deploy using best practices. Besides, who doesn’t love a challenge?

You can read more about the national effort here – http://www.transportationops.org/spatchallenge

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}
Mike Spack

My mission is to help traffic engineers, transportation planners, and other transportation professionals improve our world.

Get these blog posts sent to your email! Sign up below.