GlidePath Prototype Application
Together the Intelligent Transportation Systems (ITS) Joint Program Office (JPO) and Federal Highway Administration’s (FHWA’s) Turner Fairbank Highway Research Center (TFHRC) Office of Operations, Research and Development (HRDO) implemented and successfully demonstrated the automated GlidePath prototype application. GlidePath is the Nation’s first application of a Cooperative Adaptive Cruise Control (CACC) system that automatically communicates wirelessly with a traffic signal and controls a vehicle’s speed in an eco-friendly manner. The application leverages vehicle-to-infrastructure (V2I) communications to enable an equipped vehicle to communicate wirelessly with a traffic signal.
How it Works
When the GlidePath vehicle approaches an intelligent intersection, it receives two distinct standard dedicated short range communications (DSRC) messages describing the signal phase and timing (SPaT) and intersection geometry. With this information, and its current position and speed, the onboard computer computes its travel distance to the stop bar. DSRC messages also provide the driver with SPaT data in illustration form, which indicates signal activity (i.e., when the signal will turn from green to yellow to red). With these data, the vehicle can then compute a speed profile that maximizes fuel economy by adjusting speed either up or down to avoid coming to a full stop at the intersection, if possible. In cases where a full stop is necessary, the software holds the vehicle at the stop bar until the signal turns green and the driver issues a “Resume” command, thus ensuring that it is safe to resume forward motion. The software then accelerates the vehicle to its desired cruise speed as it leaves the intersection.
Data collected in field experiments revealed that average fuel consumption was improved in vehicles equipped with the Eco-Approach and Departure application. Results from August 2015 indicate that a driver with a DVI saw 7% fuel savings over un-informed drivers, while a driver with partial automation and the GlidePath application saw 22% fuel savings over the un- informed driver. These results show a 15% fuel improvement from a driver trying to follow a DVI speed recommendation to the partial automated GlidePath application. These improvements are due to minimizing the lag in speed changes to keep the optimal speed and approach.
- GlidePath Prototype Application Fact Sheet
- GlidePath Prototype Application Webinar (October 28, 2015)
- Glidepath Prototype Application Final Report (Coming Soon)
US-EU SWG: Emissions Visualization Demonstration
The US-EU Sustainability Working Group (SWG) was formed in 2010 with a vision to cross-leverage research and insights from studies in both the United States and Europe for mutual benefit. The purpose of the working group was to identify, research, quantify, and evaluate the environmental benefits that can be achieved from deploying Intelligent Transportation Systems (ITS) and connected vehicle applications. For the 2015 ITS World Congress, the US-EU SWG developed an emissions visualization tool that demonstrated the potential to use connected vehicle data to visualize emissions data. The tool:
- Leveraged EU Compass4D connected vehicle data (e.g., archived cooperative awareness messages (CAM) data) and infrastructure;
- Used US algorithms (i.e., CMEM) to calculate environmental performance measures based on vehicle trajectory data; and
- Produced vehicle emissions and fuel consumption heat maps derived entirely from connected vehicle data.
Visualizations were created to depict vehicle fuel consumption and emissions derived from connected vehicle data for geo-fenced roadway segment in Bordeaux, France. The visualizations show emissions and fuel consumption hotspots where vehicles emitted.
Visualizing Emissions and Fuel Consumption Data
Emissions visualizations allow transportation planners and system operators to gain valuable insights into the environmental performance of the transportation system, helping them:
- Visualize and monitor transportation-related vehicle emissions over time;
- Prioritize transportation solutions – both conventional and ITS solutions – that have the potential to reduce vehicle emissions;
- Perform before and after impact assessments to determine and track the effectiveness of newly deployed transportation solutions; and
Support real-time operational decisions to help reduce emissions, including:
- Updates to traffic signal timings (at hotspots) in real-time on arterials.
- Implementing speed harmonization strategies – optimized for the environment – on freeways.
Using the Emissions Visualization Demo tool, researchers were able to observe fuel consumption and emissions hot spots in Bordeaux including a freight delivery areas in the north and southeast, and a water treatment plant near Bordeaux.
Building from the success of the demonstration and visualization of the Compass 4D data in Bordeaux, the team explored using the USDOT Safety Pilot data from the Ann Arbor region in Michigan. The team was able to take the Safety Pilot data and using the same process from the Bordeaux visualization, created an Environmental Visualization Dashboard for the Safety Pilot data. Users have the option to select any day from April 2013, view the data (Carbon Dioxide, Carbon Monoxide, Oxides of Nitrogen, Hydro Carbons, or Fuel use) by time of day and get details on the number of data points, unique vehicles, and weather conditions for the selected time.