Rural highways are disproportionately and unnecessarily dangerous

When Southern Californians think of commuting to work or taking our kids to school, we often envision giant freeways, high occupancy lanes, the occasional toll road, and of course, traffic. However, the reality for millions of Californians is that their daily commute involves traveling along rural two-lane highways. Our state and county governments are required to maintain more two- and three-lane rural highways than they do freeways. And sadly, because those rural roads tend to traverse areas with smaller populations, lower property values, and smaller tax bases, they tend to be neglected. Put another way, a rural roadway cutting across the agricultural fields of northeast Ventura county is destined to receive far less maintenance than a segment of the 405 cutting through downtown Los Angeles.

Nationally, more than half of all traffic fatalities and more than two-thirds of all roadway departures occur on two-lane undivided highways. These numbers hold true across California as well. While these numbers are tragic, why should you care? The reason is because there is a pervasive problem across our state where people are being needlessly injured and killed in preventable collisions.

The genesis of this article stems from two cases I've taken to verdict against Caltrans in the past five or six years where a 3-4" drop off at the edge of pavement along a two-lane roadway resulted in devastating outcomes. Thankfully the civil justice system was able to help, in part, to restore the injured victims. But if the money paid in verdicts had instead been used for regular road maintenance, far more lives could be saved.

Think of it this way: you're driving at 55mph along a rural two-lane road, the road begins to curve, or perhaps you need to move your vehicle over when confronting a large 18-wheeler hugging the centerline, and suddenly your passenger side tires drop off the edge of pavement into the dirt shoulder. According to Caltrans maintenance standards dating back forty years, the vertical height differential at the edge of pavement "shall not exceed 2 inches." However, the next time you travel along a two-road way in your community, you are bound to find huge expanses of lane miles where this standard is not maintained. As your vehicle drops off the edge of pavement, a driver's natural reaction is to try and get back on the road. When confronted with a 3-4" dropoff, the tires on most passenger cars and light trucks will struggle to remount. (For perspective, consider that the curb on your city sidewalk is generally 5" tall.) At some point, due to driver input or the fact that the drop-off gradually gets shorter, your vehicle's tires are no longer scrubbing the pavement edge. Suddenly, your vehicle over-responds and you're on the other side of the highway. Below is a diagram of a typical overcorrection. The vehicle departs the roadway - often on a curve. It experiences a tire scrubbing as it attempts to re-enter and the vehicle over-responds as a result of the input and then loss of friction upon remount and a cross-centerline, head-on collision ensues.

According to NHTSA's Fatality Accident Recording System, 53% of fatal traffic crashes can be attributed to roadway departures. In relative terms, fifty-nine people will die in a roadway departure crash in this country today. That's 1 fatality every 24 minutes. Pavement edge drop off conditions in excess of 3" are commonplace on undivided two lane highways throughout this country and this state. It appears to be a consequence of lack of appreciation of the danger by many state Departments of Transportation (DOTs), lack of funding priorities amongst DOTs, and a failure of DOT maintenance personnel to appreciate the need to remediate these conditions.

This is an easy fix. Preventable collisions can and should be avoided. Unlike many dangerous roadway conditions, eliminating drop offs does not require major capital investment, high level engineering analysis, or significant resources. It merely requires maintenance personnel to push the dirt back up to the edge of the roadway. Shoulder backing, as it's known, generally requires nothing more than a small crew with simple tools to safely remediate these conditions. Caltrans' own standard to back fill (or shoulder back) drop offs in excess of 2" has been in place for over 40 years, and yet these types of crashes continue to represent an inexcusable majority of roadway departure fatalities.

Thankfully, not all hope is lost. Solutions exist to manage these dangerous conditions. However, California needs to be aggressive in adopting such standards in new construction and ensuring that current roadway infrastructure is properly maintained to the existing standards. The latest and most accepted solution to this problem is known as a "safety edge," which is accomplished by placing a simple, inexpensive, and effective "shoe" to the back of an existing paving machine that results in a gentle, recoverable roadway edge.

Not only is the safety edge safer for the motoring public, but it also has an added benefit to the state. For instance, compaction of the asphalt at the roadway edge is improved (requiring less maintenance in the future); the roadway edge is more durable (as testing has shown that heavy truck traffic on the edge, which often causes degradation of the edge and greater drop-offs, is virtually eliminated); and reduction of tort liability for serious injuries and deaths.

The cost for installing a safety edge is negligible. For approximately $3,000 (a one-time cost) the "shoe" can be added to any existing paver and there is no cost for additional paving materials (e.g. asphalt). In fact, there's likely a savings in actual asphalt because much of it sloughs off and is lost at the roadway edge in traditional paving operations. The safety edge shoe utilizes that material, keeps the costs down, and makes the roadway safer. For all of us.