Narrow Rural Lanes — 23rd Annual Highway Report

Percent of Rural Other Principal Arterials with Narrow Lanes
2017 Annual Highway Report

Narrow lanes on major rural primary roads lead to sight visibility and design issues that create safety problems. The national design standard for lane width on major rural roads is generally 12 feet, and few major rural primary roads could be improved without widening lanes to that standard.

In 2015, about  9.78% of rural other principal arterials (8,733 miles out of 89,288) had narrow lanes less than 12 feet wide (Table 17, Percent of Rural Other Principal Arterials (ROPA) with Narrow Lanes, 2013, Figure 8). This is worse than the 8.91% in 2013, the last time this assessment was completed. For 2015, seven states reported no narrow-lane ROPA mileage, while four states (West Virginia, Virginia, Pennsylvania and Vermont) reported at least 40% of the ROPA network had narrow-lane mileage.

In 2015, a majority of states (30 of 50) reported narrow-lane ROPA mileage decreasing or remaining constant. California and Vermont led the way with decreases of 9.6 and 7.0 percentage points, respectively. The remaining 20 states saw some worsening, with six states seeing double-digit increases. (As metro areas grow, rural roads are reclassified as urban roads. The remaining rural mileage is smaller but has the same or almost the same amount of narrow lanes, resulting in a higher percentage of narrow rural arterial lanes.) New Mexico, Alabama, Hawaii, Maine, West Virginia and Virginia reported increases of 28.7, 20.5, 17.7, 17.0, 16.5 and 11.6 percentage points, respectively. The increases in these six states are the primary factor in the overall increase in ROPA narrow-lane mileage.

Percent of Rural Other Principal Arterials with Narrow Lanes