August 1, 2007
Every year more than 5,000 pedestrians are killed by drivers in the United States. At corporate and industrial campuses employees take their chances against traffic and delivery trucks as they cross between buildings. At hospitals, schools, airports and event centers visitors put themselves at risk just to reach the facilities.
How can companies better protect their customers and employees from pedestrian – vehicle accidents? A solution that addresses this problem is the use of in-roadway warning light systems (IRWL).
IRWLs were invented in the mid-1990s as a tool for improving safety at uncontrolled â€” or mid-block â€” crosswalks. IRWL systems consist of tough-shelled lighting devices that are installed in the roadway and linked to an activation mechanism. The devices project a bright flashing light towards approaching traffic â€” similar to airport runway lights â€” when activated. Typically the lights are activated for a fixed crossing duration when a pedestrian presses a push button.
Adoption of IRWL systems began in earnest after they were listed as an approved traffic warning tool in 2000 in the Manual on Uniform Traffic Control Devices (MUTCD), the U.S. Federal Highway Administration’s standards guidelines. Since that time IRWL systems have been installed by municipalities, business parks, theme parks, hospitals, schools, and industrial facilities. As a traffic warning tool, rather than a traffic control tool, IRWL systems are subject to much lower liability for the installing entity. Their use is an attempt to improve driver warning, and safety, at crossings.
Dell campus installation
As an example, the city of Round Rock, Texas, recently installed three in-road warning light systems at crosswalks at Dell’s sprawling headquarters campus. City streets separate buildings in the campus and Dell had experienced accidental employee injuries and even deaths over the years. The warning light systems include crosswalk signs enhanced with LEDs that flash when pedestrians are crossing.
Research shows that IRWL lights effectively reduce traffic approach speeds and increase compliance with pedestrian crossing regulations. Kay Fitzpatrick and her colleagues wrote in a report, “Improving Pedestrian Safety at Unsignalized Crossings,” that “In-roadway warning lights have increased driver yielding to the 50 to 90 percent range. Additionally… in-roadway warning lights typically increase the distance that motorists first brake for a pedestrian crossing, indicating that motorists recognize the pedestrian crossing and the need to yield sooner. These results have been even more dramatic at night when the in-roadway warning lights are highly visible.”
In “Engineering the Roadway Visibility Information System,” Mary Cimo wrote that the addition of an IRWL system “reduce(d) the mean speed at which vehicles approach the crosswalk, as well as the mean number of vehicles that pass over the crosswalk while a pedestrian is waiting, as compared to a clearly striped crosswalk without in-pavement lighting.”
Whether the lights are amber â€” signifying the need for caution â€” or they are red â€” signifying the need to stop â€” inroad lights convey an unmistakable message to drivers approaching them. In-road lights are quickly associated with the presence of pedestrians or some other imminent need for caution. They are especially useful for avoiding a common pedestrian vehicle accident: a driver in a center travel lane on a multi-lane road does not see and stop for a pedestrian that a driver on the curbside lane does stop for. In-road lights flashing directly in front of the center lane driver warn him or her of the presence of a pedestrian in a crosswalk
Given the warning effectiveness of in-road lights, other non-crosswalk applications for their use have emerged. For example, in-road lights can be used to warn truck drivers approaching loading bays about vehicles leaving a warehouse exit that crosses their path.
In-road lighting systems are often powered by 120V AC or they can be solar powered. The latest designs feature systems with lights that are independently solar powered and wirelessly activated, thereby removing the need to individually wire the lights. This can reduce installation costs and permit more flexible light placement.
In-road lights can face a tough task and a tough environment. In order to command attention not only in darker times but during bright sunny days the lights must be exceptionally bright. And in northern climates the lights must endure not only the abuse of cars and trucks, but also the scraping of snowplows. Consideration of these demands should guide product selection. Given a well-selected and well-designed system, IRWL can greatly reduce your chance of having to address a pedestrian tragedy.