Figure 2. National Variation in Relative Risk of Traffic Crash On April 20.

The map displays the United States for all contiguous states and offset images for noncontiguous states. Colors denote relative increase in traffic risks on April 20 compared with control days exactly 1 week earlier and later. Green corresponds to increased relative risk, yellow to neutral relative risk, and brown to decreased relative risk (spectrum scaled by logarithm transformation). Findings show that 30 states had a relative risk point estimate greater than unity (eg, Hawaii), while only 18 states had an estimate less than unity (eg, Minnesota), and 2 states had an estimate of exactly unity (eg, Montana).