Navigation systems with eco-routing features can improve fuel economy by 15 percent.
Study of ITS applications for the environment
Date Posted

Applications for the Environment: Real-Time Information Synthesis (AERIS) Applications State of the Practice Assessment Report

Summary Information

This research sponsored by the U.S. DOT Applications for the Environment Real-Time Information Synthesis (AERIS) program examined how ITS applications and connected vehicle data can be used to support "green" transportation choices by transportation system developers, users, and operators. Although limited field testing has been done to date to examine the propensity of vehicle-to-vehicle and vehicle-to-infrastructure applications to mitigate the negative impacts of transportation systems on the environment, the body of knowledge in this area is growing. The following benefits and synthesis data were reported, some of which are well known to the ITS community.



These applications target individual drivers and interact with transportation management systems, information networks, and traffic control systems to determine vehicle performance relative to prevailing traffic conditions, and promote driving styles that lower vehicle emissions.

A variety of on-board applications such as adaptive cruise control (ACC) and eco-driving navigation systems can work with infrastructure systems such as traffic signal phase and timing (SPaT), speed advice, and enhanced map data announcing upcoming turns, ramps, and grade changes to correct drivers in real-time and promote energy efficient driving practices and behaviors. Eco-routing features, for example, that assist drivers with navigation can improve fuel economy by 15 percent by identifying more fuel efficient routes and save them up to 30 percent in mileage when searching for a parking space when appropriate information is provided. ACC pilot applications evaluated domestically and abroad indicate these systems can reduce fuel consumption up to 10 percent. Overall, combining multiple eco-driving applications was projected to reduce fuel consumption by 20 percent.

Demand and Access Management Applications

These applications use V2I telecommunications technology such as dedicated short range communications (DSRC) or toll tags and transponders to communicate with gantry-mounted equipment to reduce travel demand by controlling access to roadways, improving pedestrian and transit options, and encouraging policies that reduce peak period demand.

Findings indicate that cordon, congestion, and parking pricing programs can decrease VMT by two to three percent in congested urban networks. Internationally, pricing has been used to reduce particulate matter (PM) up to 20 percent, reduce Carbon dioxide (CO2) emissions up to 14 percent, and reduce Nitrogen oxides (NOx) up to 15 percent. Pricing with fuel taxes has potential to reduce VMT by 8 to 16 percent, however, with respect to mileage based user fees, acceptance in the United States has not been determined. Initial studies indicate that mileage based fees can reduce VMT up to 13 percent.

Commercial motor vehicles (CMV) can also use Access Management applications such as Pre-Pass to improve motor carrier safety and efficiency. These systems allow participating transponder-equipped commercial vehicles to bypass designated inspection stations and continue to move freight and reduce shipment times. In 2009, Pre-Pass saved an estimated 21 million gallons of fuel for commercial vehicles.

Logistics and Fleet Management Applications

These applications use automated vehicle location (AVL) systems, commercial fleet management systems, and parking/loading/delivery management systems to reduce emissions by optimizing vehicle maintenance, telematics, and driver, speed, and fuel management.

AVL systems can help commercial motor vehicles find more efficient routes which in effect can reduce VMT. One AVL/OBD technology solution identified in the report eliminated 44,000 pounds of greenhouse gas emissions annually from the City of Napa's vehicle fleet. Idle-off stop-start systems integrated into vehicle designs can also be monitored by fleet management systems to reduce truck emissions up to 83 percent at truck rest stops.

Freight Applications

These applications can use wireless technology to exchange of information in real-time and allow for more efficient management of freight travel and delivery. The following findings were highlighted in the report.

  • A Swedish trucking company reduced their fuel consumption by 5 to 20 percent using a real-time eco-driving performance monitoring system.
  • Platooning freight vehicles has the potential to reduce fuel consumption by 10 to 20 percent.

Traffic Management and Control Applications

These applications use adaptive signal control, incident management, ramp metering, speed management, advanced signal control, integrated corridor management (ICM), and active traffic management systems to analyze and dynamically adjust transportation assets to accommodate different types of traffic or changing conditions. The following benefits were highlighted in the report.

  • Integrating traveler information with incident management systems can reduce emissions an additional 3 percent and improve fuel economy by 1.5 percent. Incident management programs around the United States have documented fuel savings of up to 6.83 million gallons per year.
  • Studies in Minnesota proved that ramp metering projects in that state have reduced emissions by three to eight percent. Without ramp metering, emissions increase annually by 1,160 tons. However, ramp metering can have negative impacts on high demand days.
  • Speed management applications in Europe have decreased NOx emissions by up to 25 percent.
  • Adaptive signal control can reduce emissions up to 50 percent for travel in the direction favored by the signal. Travel in the direction that is not favored by the signal can increase emission up to 9 percent.
  • Traffic signal coordination and optimization can reduce emissions up to 22 percent and has a 40:1 return on investment.

Transit Applications

These applications can use a variety of ITS applications including AVL/CAD, demand responsive dispatching and scheduling systems, traveler information systems, and transit signal priority (TSP) applications to exchange information and optimize transit travel, encourage mode shift, and reduce transit emissions. The following most significant findings were highlighted in the report.

  • TSP studies conducted in England reported that bus emissions were reduced up to 30 percent. These systems, however, increased non-transit vehicle emissions up to 11 percent.
  • Federal Transit Administration research found that bust rapid transit (BRT) applications can lead to up to a 25 percent transit travel time savings in the United States, potentially increasing ridership, and reducing VMT and emissions.
  • Researchers in China found that road segments with exclusive bus lanes have 10 percent less emissions of NOx, Carbon monoxide (CO,) and PM compared to road segments without dedicated bus lanes.