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Reasons for Prohibition of Non-Emergency Parking on Highway Shoulders

Thinking of stopping on the shoulder of the highway when not absolutely necessary? Think again - it's one of the most dangerous places to be. Many drivers assume that if they parked on the shoulder of the road, they would be safe and unlikely to be struck by another vehicle. Experience proves this assumption to be terribly (and often fatally) incorrect. That is why most states have Vehicle Code provisions that absolutely prohibit non-emergency stops on roadway shoulders. Likewise, Federal Motor Vehicle Safety Standards also prohibit such stops due to the severe hazards they present to other motorists.

Many years ago, I was contacted by a young lady whose husband had recently been killed when the car he was driving slammed into the rear of a 65 feet long tractor-trailer rig parked on the shoulder of Highway 101 in Santa Barbara. Because the rig was parked many feet from the traffic lanes and the running lights of the trailer were on, the investigating CHP officers assumed that the husband had simply fallen asleep at the wheel and allowed his car to drift off the roadway and into the back of the rig, and that was the official explanation of the accident stated in the CHP report. I nearly turned down this case, but accident reconstruction and bio-mechanical experts I consulted concluded that the young driver of the car had been lulled into believing he was following a large rig which was traveling in the right hand lane of the highway and he therefore purposely aligned his car with the rear lights of the rig and realized only a split second before impact that the rig was not even moving.

Our human factors expert told the jury that years earlier the CHP instructed its officers to turn off all of their lights when pulling a vehicle over and stopping on the shoulder. They were tired of having impaired motorists slamming into patrol cars on the shoulder, and they theorized that the flashing emergency lights actually attracted impaired motorists, just as an outdoor light attracts moths. The rate of shoulder collisions with CHP cars dropped by half, but then one very unlucky motorist collided with a patrol car parked on the shoulder with its lights off and the occupant sued the State of California and won. This caused the CHP to revert to its original policy requiring emergency lights to be left on when the arresting officer was parked on the shoulder, and the rate of shoulder collisions with patrol cars quickly doubled to its original rate, thus providing compelling empirical evidence to support the "moth effect." There are many good reasons for the laws that make it unlawful to use a shoulder as a place to park in the absence of a true emergency.

Additional resources provided by the author

Local Vehicle Code
Local Department of Motor Vehicles publications
Local Highway Patrol Department
Federal Motor Vehicle Safety Standards and Regulations (U.S. Code and Federal Register)

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