Routecast: The Future of Traffic Signal Control

Here’s how Routecast works:

Surtrac reduces traffic delay by creating highly accurate models of where traffic is now, but also where traffic will be in the future, and then optimizing a signaling plan to best serve that traffic with minimal delay.
Surtrac does this by using passive detection (often video and radar detectors) meaning that travelers do not have to take any action to achieve benefit.
While Surtrac does a great job of modeling where traffic will be in the future, when it knows this information with certainty, it can optimize traffic flows even better.
With Routecast, multi-modal travelers (including pedestrians) share their route with Surtrac using either a mobile phone or connected vehicle (CV) technology built directly into their vehicle.
This route information provides Surtrac with extremely high certainty about where Routecasters will be in the future, so that Surtrac’s model of all travelers more accurately predicts the future.
This accurate predictive model makes Surtrac’s optimization decisions more effective, allowing Surtrac to further decrease delay by 20-30% for the first Routecasters, and by 30-40% at high usage rates of Routecast. The network effects from Routecast can even improve delay for travelers who choose not to share their route.

Routecast in the field:

Rapid Flow has field tested Routecast with human drivers using smartphone apps, autonomous vehicles sharing their route information using persistent cloud communication, and transit buses using their own API for location and routing information. These tests showed 20-30% lower vehicle delay when adding Routecast communication capabilities to Surtrac.
At the locations tested, this equates to 5-10 seconds saved per intersection, on average, for each Routecaster in addition to the 3-9 second improvement just from passive detection, resulting in millions of dollars of time, fuel, emissions, and safety savings at every intersection.
An early version of pedestrian access has been tested in cooperation with Carnegie Mellon University and the US DOT. The app, PedPal, is geared toward pedestrians with disabilities.
Rapid Flow is working with 2 partner cities to develop and conduct large-scale tests of Routecast.

Benefits of Routecast:

Improvements at Low Adoption Rates -- Routecast provides incremental benefit even at very low rates of adoption. Simulation and real-world testing of the Routecast solution shows that just one vehicle sharing its route can create up to 30% incremental delay improvement. This means that Routecast can deliver value in the short term, well before massive adoption of CV technology.
Positive Network Effects are Equitable and Shared by All Travelers -- as more travelers share their route, delay reduction improves for everyone, whether they are sharing their route or not. Routecasters see a benefit by reducing the uncertainty for Surtrac, not because they receive special priority. As more travelers use Routecast, the improvement seen by Routecasters improves as uncertainty is further reduced. In fact, even those who do not participate see substantial reduction in delay which increases as more of their fellow travelers use Routecast. It is worth noting that the incremental benefits from Routecast are in addition to the improvement achieved by Surtrac using passive detection alone. When added together, we’ve seen total improvements of as much as 60%.
Multi-modal -- Routecast can work for any type of traveler including pedestrians, bicyclists, people riding scooters, autos, trucks, transit, etc. In fact, it can be extremely helpful for travel modes that are difficult to detect accurately with passive detection (e.g. bicycles and scooters). A version of Routecast was even shown to improve the experience of pedestrians with disabilities. For example, vision impaired pedestrians were able to communicate with Surtrac through Routecast in order to more safely cross busy urban intersections.
Privacy -- Routecast only needs current, short term information about your route in order to be effective, and there is no need to store personal historic information, protecting the privacy of Routecasters. Rapid Flow only uses this short term information for the purpose of traffic control.
Low maintenance costs for cities -- Routecast allows for improvement beyond Surtrac with no extra hardware cost or maintenance for cities. Users bring their own connected devices, so the only added maintenance cost is a web server, which Rapid Flow maintains.
Creates Opportunity for New Funding Models -- While everyone receives substantial delay improvement from Surtrac using passive detection, the incremental benefit that Routecasters achieve provides the opportunity to charge a very small fee for the opportunity to Routecast and achieve additional delay reduction. Even at low adoption rates, these small payments could fully subsidize the delay improvement achieved by non-Routecasters, who would pay nothing. Cities could also achieve certain policy goals by providing partial or full discounts to Routecast for transit, environmentally friendly travelers (e.g. those on bikes, or electric vehicles), city residents over suburban commuters, etc.