Road undulations are one of several measures to calm traffic on local residential streets. The Institution of Transportation Engineers defines traffic calming as, "the combination of mainly physical measures that reduce the negative effects of motor vehicle use, alter driver behavior and improve conditions for non-motorized street users."
Horizontal & Vertical Deflections
Traffic calming measures fall into two general categories. Horizontal deflections, such as traffic circles, cause drivers to slow down as they alter their path. Vertical defections, such as road undulations cause drivers to slow down to avoid the discomfort of a sudden change in elevation. In both cases the physical features of traffic calming measures are intended to be self-enforcing.
Road undulations are designed to slow traffic down to 25 miles per hour. A complete description of road undulations as well as the advantages and disadvantages of these traffic calming devices is included in the Summary of Road Undulations.