Urban Arterial Lane Width versus Speed and Crash Rates: A Comprehensive Study of Road Safety

This study investigates the relationship among lane width, velocity, and accident rates to enhance understanding their impact on road safety and transportation. Analysis of data from 320 urban arterial sections in Utah indicated that narrower lane widths can improve road safety. Reduced vehicle speeds were related to narrower lanes on urban arterials, which did not result in increased collision rates. Reducing one foot in lane width led to an average speed decrease exceeding one mph. Additional factors influencing speed on urban arterials encompass the number of lanes, the existence of medians, on-street parking, roadside obstructions, and block length. Safety modeling indicated no clear correlation between lane width and total crash frequency per mile. Injury crash rates positively correlated with lane width and speed, suggesting that broader lanes and elevated speeds augment the probability of injury crashes. Additional critical elements affecting crash statistics comprised the number of lanes and the Average Annual Daily Traffic (AADT) per lane (in thousands). The study endorses the reduction of lane widths as a viable approach to augment road safety and boost urban transportation infrastructure. The results provide essential direction for policymakers and transportation authorities aiming to enhance road safety and efficiency.