V2X test beds for faster, cleaner, safer transportation

Every day on the drive home from work I hit a two-mile stretch of road with nine traffic signals. As if that weren’t bad enough amidst rush hour, the lights aren’t synchronized (at least not properly). I can’t tell you how many times I’ve sat trapped behind a red at signal four and watched signals five and six light up green, only to turn yellow as soon as I can accelerate. Meanwhile, two cars traveling in the perpendicular direction have sped off, while 30-plus parallel drivers join me in silent frustration.

Incidentally, though, about 40 miles as the crow flies northwest of that gridlock, in the small town of Anthem, AZ, a V2X pilot is underway that could help change my commute from stop to go. The Arizona Connected Vehicle Test Bed is a partnership between government (Maricopa County Department of Transportation), academia (University of Arizona College of Systems and Industrial Engineering), and industry (Savari Inc.) that has been in the works since 2009, and promises to cut travel time, fuel costs, pollution, and usher in a new standard of safety for vehicles and pedestrians alike.

V2X and the Arizona Connected Vehicle Test Bed

Given the long lifecycles of the automotive market, it should come as no surprise that traffic management systems are decades old themselves. Traditionally, the traffic management discipline used electro-mechanical signal controllers based on simple, static timers to regulate traffic flows. More recently, sensors embedded in the pavement or elsewhere nearby have been used to augment these systems by detecting the number of vehicles traveling in a given direction, usually by sensing the presence or absence of metal. Neither approach is efficient as possible, as solely timer-based systems have no consideration for real-time traffic conditions, and sensor-based systems often fail to trigger when small vehicles, motorcycles, bicycles, horses, and other forms of road transportation with low metal content are present. Furthermore, these “dumb” sensor deployments don’t provide auxiliary information about traffic patterns that could be useful to traffic management professionals and planners, such as the percentage of westbound vehicles at a light that actually proceed west, versus those that turn north or south.

Today, however, the Arizona Connected Vehicle Test Bed, along with sister pilots in Ann Arbor, MI, Palo Alto, CA, Washington D.C., Virginia, and New York, are leveraging V2X sensors based on dedicated short range communications (DSRC) technology to improve on past approaches. Currently in phase two of the pilot, the Anthem Test Bed uses road side units (RSUs) fixed to light poles in conjunction with aftermarket on board units (OBUs) mounted in buses and emergency vehicles. The RSUs function as a type of base station for intersections along more than two miles of test bed corridor, and analyze requests submitted by OBUs to create maps of the surrounding area comprised of vehicle data (vehicle type, direction, etc.) and information from traffic signal controllers. Information from the RSUs and OBUs, both developed by Savari Inc., is then processed using algorithms developed by a team from the University of Arizona, which prioritize traffic flows based on the number and type of vehicles attempting to advance. For instance, in this limited pilot, first priority is given to emergency vehicles, followed by mass transit vehicles, and an on-board display in buses indicates to the operator when an emergency vehicle is approaching. In other test beds, such as Ann Arbor, this functionality has already been extended to regular passenger vehicles, and the participants hope to extend the architecture to semi trucks as well in order to help reduce pollution, wait times, and accidents.

Serious about safety and software

Although the company develops the RSU and OBU hardware that makes test beds such as the one in Anthem possible, Savari Inc.’s primary focus today is on middleware and application development. Using a cloud-based system that pulls analytics from OBUs and RSUs, Savari has also developed apps that promote driver awareness and driver safety, as well as smartphone apps for the visually impaired or otherwise-disabled pedestrians that allow them to communicate with the traffic controller, if they need additional time crossing a street. This also has implications for phones communicating directly with vehicles by means of DSRC, as wireless chipsets in modern smartphones can be manipulated for compatibility with DSRC’s 5.9 GHz frequency band.

Imagine how effective this technology could be in all aspects of transportation if rolled out on a massive scale. Data from the previously mentioned pilots is being reviewed by the U.S. Department of Transportation to potentially create rules or mandates around DSRC technology in cars (and/or LTE in the future). But for now, think twice about switching out of lanes when a bus is ahead of you. It may just have an OBU that helps you make the next light.