A recent study by the Michigan Department of Transportation (MDOT) and Western Michigan University shows new signs and signals make roads safer for older drivers. Michigan’s aging population has resulted in an increase in the number of older drivers involved in traffic crashes. The number of drivers age 65 and older involved in crashes in Michigan increased by 2.4 percent from 2004 to 2013, even as the number of all drivers involved in crashes dropped by 23.8 percent during the same period.
In 2004, MDOT began implementing engineering countermeasures addressing the needs of older drivers.
• The use of Clearview font on guide signs, which improve legibility by minimizing blurring around the edges of the letters.
• The use of fluorescent yellow sheeting, a new, brighter color for warning signs that is more visible.
• Box span signal configuration, in which traffic signals are suspended along all four sides of an intersection, to improving safety and visibility.
• Pedestrian countdown signals, which show the number of seconds remaining to safely cross the roadway. These signals help pedestrians decide whether to start crossing an intersection or adjust their walking speed.
• Arrow-per-lane signing, which clarifies navigation paths with a directional arrow above each limited access highway lane.
Kimberly Lariviere, MDOT Strategic Highway Safety engineer, is the project manager.
“The benefit-cost ratio for all of these previously used devices was very good, and some were exceptional,” Lariviere said. “This research confirms that the improvements MDOT started making 11 years ago for older drivers were wise investments that we should continue implementing.”
The improvements were reviewed in two ways. Researchers surveyed 1,590 Michigan drivers and pedestrians in Detroit, Grand Rapids, Kalamazoo, and Lansing to learn their perceptions of the improvements. Historical crash data, before and after implementation, also was analyzed to determine the impacts of the improvements on safety.
The surveys revealed drivers preferred the improvements over the traditional alternatives. Data analysis showed all five improvements offered cost-effective ways to reduce crash rates among all drivers, specifically among older drivers.
This project confirms that all five of the improvements studied provided good safety benefits for the amount of money invested, and several produced exceptional benefit-cost ratios. Researchers recommend continuing to install them in appropriate locations.
More details are available in the MDOT research spotlight report “Evaluation of Michigan’s Engineering Improvements for Older Drivers” online. www.michigan.gov/documents/mdot/RC1636_Spotlight_506683_7.pdf