Page 37 - GCN, August/September 2017

could become a Federal Motor Vehicle Safety Standard, just like airbags or rearview mirrors.
Are there any cars that have implemented it already?
Yes, there is one, and that’s the General Motors Cadillac CTS. Japan uses a different frequency, but Toyota already offers DSRC in three of its Japanese models as an option.
How will DSRC be used?
The first application is in vehicle-to- vehicle communication. Cars in close proximity can use an electronic brake light that broadcasts that braking information to other cars within 1,000 feet. In the future, this could become autonomous emergency braking, which uses sensors like camera or radar that detect an imminent threat, and the
car brakes itself. Onboard sensors and [vehicle-to-vehicle] communication will provide redundancy to make sure the information is correct.
What sorts of applications use vehicle-to-infrastructure communication?
Today, there are not many V2I projects. Many of the applications use signal phasing and timing. Imagine if you’re coming close to an intersection and the traffic signal phasing and timing are sent to you in advance. Not only do you see the current state of the light, you know when it will change. So you can use that for what we call eco-driving purposes.
The second — and probably longer- term but certainly immediately doable application — is adaptive traffic signal control. So imagine a traffic signal collecting information from various directions. By looking at how far away a car is, it can figure out the queue length at the intersection. You should be able to figure out the traffic flow and change the balance of the red and green signals for all of the directions to help move traffic more efficiently.
How hard is it to install the roadside units that will be collecting the information from cars?
In most big cities, the important intersections are already wired and powered. They have a traffic control cabinet, and the phasing and timing can be controlled from a traffic
control center. We already have the communication network and the power necessary, so all you need to do is add wireless communications.
DSRC is nothing but a Wi-Fi. It
is a special standard, it is a little
bit different, but fundamentally
it is a Wi-Fi. So to hook up
important intersections today with communications and power shouldn’t cost more than $2,000 to $3,000 per intersection.
How does a locality decide where to put those units? People have to want to solve a problem, typically congestion. Collecting data
is not the point; using the data is the
GCN AUGUST/SEPTEMBER 2017 • GCN.COM 37
PHOTOS FROM THE UNIVERSITY OF MICHIGAN