Phoenix city crews are installing new street signs in downtown Phoenix to discourage bicyclists from riding against traffic.

Arizona law requires bicyclists to ride with traffic. In Phoenix, between 2009 and 2013, nearly a third of bicycle crashes involved wrong-way riders. The new signs include a warning message and are positioned to be seen by bicyclists wrongfully riding against traffic.

Traffic experts warn that when drivers turn onto a street, they may only look for traffic coming from one direction. Riding against traffic means turning motorists may not see bicyclists.

Kerry Wilcoxon is the head of the Safety and Neighborhood Traffic Section for Phoenix’s Street Transportation Department and discussed the city’s effort to remind bicyclists to ride with traffic, rather than opposite it.