THEA Pilot Project: Key Terms
CSW – Curve Speed Warning
Alerts driver approaching curve with speed safety warning
DSRC – Dedicated Short Range Communications
One-way or two-way short- range to medium-range (about 1 kilometer) wireless communication channels specifically designed for automotive use.
I-SIG – Intelligent Traffic Signal
Uses both vehicle location and movement information from connected vehicles with infrastructure measurement of non-equipped vehicles to improve the operations of traffic signal control systems.
OBU – On-Board Unit
Device that enables vehicles to communicate with roadside infrastructure.
PED-X – Pedestrian In Signalized Crosswalk Application
Alerts vehicle to the presence of pedestrian in a crosswalk
RLVW – Red Light Violation Warning Application
Enables a connected vehicle approaching an instrumented signalized intersection to receive information from the infrastructure regarding the signal timing and the geometry of the intersection
RSU – Roadside Unit
Device that enables roadside infrastructure to communicate with connected vehicles.
V2I – Vehicle-To-Infrastructure
Allows wireless communication between infrastructure and vehicles
V2V – Vehicle-To-Vehicle
Allows wireless communication between vehicles
The city of Tampa, Florida is only weeks away from implementing new technology that aims to completely reduce traffic congestion and improve safety in its central business district.
Robert Frey, planning director for the Tampa Hillsborough Expressway Authority (THEA) told Informa that the city will on 1 July launch its Tampa Connected Vehicle pilot. The program will use innovative vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications technology to improve safety and traffic conditions in the 0.8-square mile area.
“We’re in the final testing,” Frey said. “We’re seeing that our apps are working properly after adding the security layer. That’s not always a given, so we had to work through that.”
Preparations for the pilot program have been ongoing since 2015. That year the US Department of Transportation (USDOT) awarded THEA a $17 million contract to enable safe, interoperable, networked wireless communications among vehicles,infrastructure, and personal communications devices in the area.
Hillsborough County’s population had been expected to grow by 47.7 percent from 1.21 million to 1.78 million between 2010 and 2040, according to a 2016 USDOT Intelligent Transportation System’s Joint Program Office report.
That year Siemens — as part of a team also comprised of HNTB, the University of South Florida Center for Urban Transportation Research, and local marketing firm Global 5 Communications — agreed to provide the critical curve speed warning (CSW), pedestrian in signalized crosswalk (PED-X) and red light violation warning (RLVW) safety applications which make up the pilot program’s V2I component.
Wendy Tao head of the Smart Cities Portfolio for Siemens’ Intelligent Traffic Systems said that the technology is giving vehicles a chance to communicate with infrastructure.
“You’ve got a roadside unit (RSU) that’s using dedicated short range communications (DSRC) on the 5.9MHz spectrum to collect information from the traffic signal and send to the on-board unit (OBU).”
Tao explained that data such as a map, or a diagram of how vehicles enter a particular zone, is broadcast from the RSU at 10 times per second. The OBU processes the data and sends additional data to the RSU.
DSRC was designed to operate in a mobile environment to achieve both low latency and high reliability. According to USDOT, it has very short time delays and message delivery is assured, particularly in a dynamic mobile environment. DSRC also provides vehicles with 360-degree awareness of roadway conditions, nearby vehicles as and potential hazards at distances of up to 1,000 feet.
The V2I technology
Siemens’ CSW application allows connected vehicles to receive information such as a recommended speed from intelligent signal technology (I-SIG) applications positioned on the RSU. The information from the RSU is relayed to the vehicle’s OBU, which notifies the driver using the rear-view mirror as an interface.
The PED-X Warning application also allows roadside infrastructure to communicate with the vehicle’s OBU. But, instead of determining a potential hazard, the app indicates the possible presence of pedestrians in a crosswalk. Unlike the CSW application, the PED-X warning can indicate whether a pedestrian call button has been activated, as well as relay information from pedestrian sensors.
The OBU comes with an RLVW application that warns drivers before they run red lights using the vehicle’s speed and acceleration profile, along with the signal timing and geometry information from an RBU. Siemens will adapt the application to warn drivers of wrong way entries onto the downtown end of the Lee Roy Selmon Expressway’s Reversible Express Lanes.
The equipment used for the pilot include traffic signals, RSUs, OBUs, smartphones and the existing computers located in the city’s transportation management center (TMC), which manages all signals in the city.
Frey noted that while the system currently provides drivers with information about road conditions and pedestrian traffic, an autonomous system is not particularly far-fetched.
“The technology exists,” Frey said. “It is more about perfecting the technology, public acceptance and the logistics of deployment. It is a process that we are just beginning.
THEA’s pilot project is only one of many that Siemens is currently involved in. The company in 2017 agreed to donate 25 DRSC roadside units valued at $385,000 to Columbus, Ohio’s Smart Columbus initiative in order to advance the implementation of connected vehicle technology.
Smart Columbus’ Program Manager Mandy Bishop said that the units will be installed in late 2019, in addition to other traffic signal units.
Siemens has also established “centers of excellence” in Ann Arbor, Michigan and Seattle, Washington. The centers serve as living labs where Siemens’ technology can be tested and modified to address both cities’ needs, as well as provide guidance for other cities.
Tao said that Ann Arbor has advanced Siemens’ adaptive signal control implementation system known as the Split Cycle Offset Optimization Technique (SCOOT) to include features such as customized maps and a new user interface slated for release this year.
More importantly for commuters, Ann Arbor’s use of SCOOT improved travel times by 10-20 % on average.
Tao also noted that the Seattle center of excellence successfully developed a means of connecting data from bluetooth detectors to modify signal timing plans and signal timings. She explained that the technology allow smartphone devices to trigger a threshold volume count outside parking garages when events such as concerts or sports games end.
The data is pulled into an advanced traffic management system called Concert which can extend the amount of green time at signals outside of the parking garage exits and reduce the amount of congestion that often occurs when large groups of vehicles exit the traffic at once, Tao said.
“These living labs create new ways to manage traffic,” Tao said. “Other cities can look at what’s being developed and say ‘How can we do that?’”