Overall Effectiveness Concerns: This countermeasure has not been systematically examined. There are insufficient evaluation data available to conclude that the countermeasure is effective.
The purpose of Share the Road programs is to increase drivers’ awareness of bicyclists, as well as improve both bicyclist and driver compliance with relevant traffic laws. The National Strategies for Advancing Bicycle Safety was developed from a July 2000 conference of bicycle advocates, injury prevention specialists, and government representatives (NHTSA, CDC, & FHWA, 2001). The result was five goals, each with a series of strategies and action steps. The first goal, Motorists Will Share the Road, called for the creation of a “coordinated Share the Road public education campaign that can be adapted at the State and local levels.
For an example of communication and outreach material, see www.pedbikeinfo.org/topics/drivertraining.cfm. AAA created a series of Share the Road promotional videos in partnership with the Share the Road Cycling Coalition and the Canadian Automobile Association. These videos can be accessed at https://exchange.aaa.com/safety/bicycle-safety.
Effectiveness: Share the Road awareness educational information can be effective in increasing knowledge and appropriate attitudes, but as with other awareness programs, there is limited evidence of behavior change, and no evidence of reductions in crashes.
Some limited evidence suggests that Share the Road signs can have positive effects on drivers’ lane position and speed when passing bicyclists. Kay et al. (2014) conducted field studies examining drivers’ passing behavior on a rural two-lane highway before and after the installation of “Share the Road ” signs. Although the presence of the sign did not significantly reduce crowding, fewer drivers traveled in the rightmost lane position after the signs were installed. Drivers also reduced the vehicle speed by an average of 2.5 mph when passing bicyclists in the presence of the sign. In a limited study, shared-use arrow (“sharrow”) pavement markings were shown to influence bicyclist lane position toward the sharrow marking in the shared-use lane (Pole et al., 2015). Similarly, adding dashed lines on either side of the sharrow (called dooring-zone markings) led to safer bicyclist lateral positioning that was farther from parked vehicles, while also reducing motor vehicle passing (Kassim et al., 2018). On the other hand, a 3-year before-and-after analysis conducted in Chicago using dooring crash data (a crash where a cyclist collides with an open car door) found that dooring crashes increased more in blocks where sharrows were added than in blocks where bike lanes were added or where no improvements were made (Turnbull, 2017). Although these studies do not provide conclusive evidence of safety improvements, they suggest that these infrastructure interventions may have the potential for positive effects on both driver and cyclist behavior, but more research is needed.
Some cities and States are specifically changing their Share the Road signs to indicate that bicyclists may occupy the full lanes. This is because Share the Road is perceived differently by different users and not always in its intended way to encourage motorists to look out for and drive safely around bicyclists.
Costs: Medium, including the costs to develop new publications or tailor current ones. The material can be delivered as training for specific target audiences, such as new drivers or all high school students, or drivers as they renew their licenses, or general communications and outreach intended for mass media delivery.
Time to implement: A good campaign, including market research, message development and testing, and implementation, will require at least 6 months to plan and implement.