Our first scenario occurs in downtown Sunnyside, a city in the Southern United States. Sunnyside has a busy signalized network and is plagued by many of the same issues typical of large urban centers. Its intersections are complex and congested, it is a transit destination, and parking is limited. Pedestrian presence is high, but air quality and safety concerns mean that Sunnyside is not pedestrian-friendly.
Recognizing these issues, Sunnyside’s relevant stakeholders convene and identify the main challenges that they face. Heavy vehicle congestions during peak hours affect transit vehicle schedule reliability and other mobility concerns. Safety concerns include vehicle-pedestrian conflicts and vehicle-to-vehicle left hand turn crashes at intersections. Vehicle emissions exacerbate local air quality hot spots, affecting the local quality of life, while poor vehicle progress and idling leads to wasted fuel and additional excess emissions.
With these six problems identified, the local stakeholders set three key improvement targets. In order to increase transit reliability, 90% of transit vehicles will have to remain on schedule. A 50% reduction in pedestrian-vehicle conflicts will satisfy the goal to improve pedestrian safety. Lastly, the stakeholders set a target for a 20% reduction in emissions in an attempt to improve local “hot spot” air quality. With these broad goals in hand, the stakeholders are ready to choose from the full catalog of application solutions.
This is the full catalog of USDOT applications designed to address mobility, safety, and environmental concerns. In order to improve transit reliability, the stakeholders select the Transit Signal Priority and Connection Protection (T-CONNECT) applications. Connection Protection is an application that allows you to phone a bus and inform them that you are running late, allowing either that bus or a future one to delay its departure.
To improve pedestrian safety, the stakeholders select the Pedestrian in Signalized Crosswalk, Intersection Movement Assist (IMA), and Mobile Accessible Pedestrian Signal System (also known as PED-SIG) applications. These applications act in concert to improve pedestrian access, speed of movement, and safety within intersection and crosswalks.
For environmental concerns, the stakeholders select the Eco-Approach and Departure at Signalized Intersections and Eco-Traffic Signal Timing emissions applications, developed under the AERIS program. These applications not only reduce fuel usage at the start-up and acceleration phases, but improve mobility through a more predictable and constant traffic flow.
Here is an overview of the seven applications selected to improve transit reliability, pedestrian safety, and “hot spot” air quality in Sunnyside. If properly executed, these applications will provide benefits and act synergistically to improve the network.
With the additions of the transit applications Transit Signal Priority and T-CONNECT to the deployment concept, our projected impacts include fewer missed transit connections, 90% transit vehicle schedule adherence, reduced transit vehicle emissions, and higher transit ridership as a consequence of improved service. This slide illustrates a passenger on the rear bus using the T-CONNECT application to hold the forward bus, while signal prioritization expedites the rear bus’s trip.
The PED-SIG, Pedestrian in Signalized Crosswalk Warning, and IMA applications will result in a 50% decrease of pedestrian-vehicle conflicts, improved mobility for both pedestrians and vehicles, and reduced emissions due to improved traffic flow. This slide illustrates how mobile technology will be able to warn drivers of pedestrians in a crosswalk, while the blue dots in the crosswalk illustrate a redundant sensor system that accomplishes the same.
The addition of the Eco-Approach and Departure at Signalized Intersections and Eco-Traffic Signal Timing applications will result in a 20% decrease in vehicular emissions, improved intersection throughput, a 10% reduction in vehicle delay, and the flexibility to optimize for mobility or environmental concerns depending on the circumstance. For example, morning or evening rush hour periods would be candidates for an increased system reliance on mobility applications, while a day with poor local air quality would make environmental applications appropriate. This slide illustrates a vehicle platoon moving at a steady speed and equipped with the forewarning that the traffic signal will remain green.
This slide illustrates downtown Sunnyside with an integrated deployment concept in place. The new and improved Sunnyside enjoys better weather conditions and is more pedestrian friendly and accessible. The messages that pass wirelessly through the network components support and complement a variety of applications and sub-applications, which in turn support each other and amplify their collective effects. These mobile applications create exciting new technological capabilities, while also reinforcing the effects of existing technologies and infrastructure.
