The field of Intelligent Transportation Systems (ITS) has

witnessed significantly increased activity in recent years,

with the application of modern control, communications,

and information technologies to vehicles and roadway

infrastructure. In general, ITS can be categorized into three

major target areas: Vehicle Systems, Traffic Management

Systems, and Travel Information Systems.

The primary objectives of ITS have been focused primarily

on improving safety and increasing mobility and associated

transportation efficiency. In addition, it is now well known

that ITS technology can be used to reduce transportationrelated

environmental impacts. These environmental

impacts include pollutant emissions that lead to poor air

quality, as well as energy consumption and greenhouse

gas (GHG) emissions. Over the years, we have seen many

ITS programs focusing on safety and mobility also having

significant environmental benefits. These benefits range

widely due to a number of variables such as type of

application, technology used, and pre-existing condition

before deployment.

In recent years, a number of ITS programs have emerged

that are specifically designed to minimize the

environmental impacts of transportation. Many of these

environmental-ITS programs take advantage of the

“connected vehicle” technology that enables vehicles to

communicate with each other as well as with roadway

infrastructure, and vice versa. These environmental-ITS

programs typically show energy and emissions reductions

on the order of 5% to 15%.

Most of the environmental-ITS programs are additive, therefore greater benefits may be

achieved when a multitude of these programs are put into place. On the other hand, the

mobility and safety impacts of environmental-ITS programs are not currently well understood.

As more of these programs are deployed, comprehensive impact assessments of their

environmental, mobility, and safety performances are needed.

When planning the deployment of ITS programs that will improve traffic flow and reduce

congestion, it is important to also consider any potential induced demand effects, which may

result in an overall increase in vehicle miles traveled (VMT) after the ITS programs have been

deployed for a certain period of time. Such increase in the amount of travel is undesirable as it

may wash out the mobility and environmental benefits of the ITS programs. It may be that to

counteract these effects, the ITS programs may have to be coupled with some specific travel

demand management measures such as pricing.