SAFETY EVALUATION OF CONVERTING ON-STREET PARKING FROM PARALLEL TO ANGLE

To increase the supply of parking in the central business district of Lincoln, Nebraska, the city converted parking on several streets from parallel to angle. The conversions were made on streets that had enough room to permit the removal of a traffic lane to provide the additional street width needed for angle parking without increasing traffic congestion. The safety effects of converting on-street parking from parallel to angle were evaluated and the cost effectiveness of the parking conversion was determined. The conversion resulted in a significant increase in the number of parking-related accidents; the number of parking-related accidents per million vehicle miles also increased significantly. But when the increase in accident exposure caused by the increase in parking activity was considered, there was no significant increase in the parking-related accident rate, nor was there a significant change in the severity of the parking-related accidents. The on-street conversion was cost effective because the increase in accident costs resulting from the conversion was lower than the cost of providing additional off-street spaces.