Incidents and Congestion
Quickly detecting, responding to and removing incidents is essential to maximizing the efficiency of our existing freeway system. The daily vehicle-miles traveled in the seven county metro area has grown by 112 percent since 1980, while the number of lane-miles added to the highway system has grown by only 5.2 percent*. Each year the metro area experiences between 7,000 and 9,000 freeway crashes and it is estimated that the total number of incidents is eight times this number.
An incident blocking one lane of a three-lane freeway reduces the freeway capacity by 50 percent and an incident blocking one lane of a two-lane freeway reduces the freeway capacity by 65 percent. Even a crash located on the shoulder can reduce the freeway capacity by up to 17 percent, while a stalled vehicle on the shoulder can reduce capacity by 5 percent**. Each minute of incident duration results in 4 to 5 minutes of additional delay***.
Freeway service patrols around the country
The use of freeway service patrols similar to FIRST to combat congestion has grown substantially over the past decade. Over 70 freeway service patrol programs operate around the country with 45 programs initiated since 1992. The majority of these are funded and run by state DOTs and are highly cost effective. Of the 49 Metro areas in the US with populations over one million, only two do not have a freeway service patrol operating.
*Source: Trunk Highway Sufficiency File, Office of Investment Management
**Source: Traffic Incident Management Handbook, FHWA, Nov. 2000
***Source: ITE Journal, March 1992