ow safe is the intersection near your child's school? How many car accidents have occurred near your home?

Citizens concerned about traffic safety issues such as these now have a new tool at their disposal.

The Crash Outcome Data Evaluation System, or CODES, links motor vehicle crash data with medical data to develop a better picture of motor vehicle injury and the effectiveness of protective devices such as seat belts and motorcycle helmets. The CODES Geographic Information System, or GIS, allows users to retrieve information and view it on a map.

The public-use version of CODES, available at the state Department of Public Health in Hartford, lets users find all the accidents that occurred at a particular location or find all the accidents of one type that occurred statewide. For example, people can enter their own address in the system to discover how many accidents have taken place near their home. Or traffic planners can request a list of all the fatal accidents involving pedestrians throughout the state to determine which areas are most dangerous.

The information available through the system is especially important to those interested in recognizing and changing problems.

"This is their way of getting the evidence, so they can advocate for change," says Ellen Cromley, a professor of geography who created the system with the state Department of Public Health.

Twenty states, all funded by the National Highway Traffic Safety Administration, are participating in CODES, which evolved from a congressional mandate to report on the benefits of regulations requiring the use of protective devices such as helmets and seat belts. Connecticut is the only state that has developed a statewide GIS to be used with CODES, Cromley says.

To develop CODES, Cromley worked with data from police accident reports for 1995 and 1996 that her colleagues linked to emergency department, hospital inpatient, trauma records and mortality records. The researchers used data from 1995 and 1996 because, when the project began, those were the two most recent years with complete data.

All collisions that occurred on state or federal roads and all collisions on local roads that indicated a fatality or injury were included in CODES, Cromley says. The medical records databases include records from all but one of the hospitals in the state.

The linked data identifies the types of injuries and costs resulting from specific driver, vehicle and crash characteristics. The data can be used in crash analysis, problem identification, and program or policy development.

For example, the system can measure the effectiveness of seat belts and child safety seats in preventing and reducing the severity of injuries and fatalities. It can also look at the cost and severity of injuries resulting from certain driver behaviors, such as speeding.

With CODES GIS, users can monitor injuries by type and location of occurrence, and implement and evaluate intervention strategies. The system represents one of the first statewide public health surveillance systems to be linked to a GIS.

Allison Thompson