Nighttime visibility is a key safety factor for Delaware roads, just as it is elsewhere. As part of the Delaware Strategic Highway Safety Plan, the Delaware Department of Transportation (DelDOT) has treated new areas across the state with enhanced highway lighting to combat key areas and they emphasize good maintenance of pavement markings and signs. Locally maintained roads are similarly in need of examination for areas to improve.
The Federal Highway Administration’s Every Day Counts initiative on nighttime visibility is a fresh focus area as well and there you can find proven countermeasures and other resources, such as the Pedestrian Lighting Primer.
Many of the countermeasures available are already, or should be, in our regular maintenance schedules, but conditions change and it is helpful from time to time to have a fresh look at key risk areas and assess whether we have practices in place and they are well maintained.
Pavement markings are a good place to start. Whether they are “long lines” (double yellow centerlines, white edge or lane markings, etc.) or “short lines” (stop bars, crosswalks, “sharks teeth” yield markings, etc.), it is important that they be consistent with the Delaware Manual on Uniform Traffic Control Devices (MUTCD) in terms of location, size, and compatibility with other devices, such as signs. Pavement markings should be retroreflective or adequately lit with street lighting, they should be bold and retroreflective. The problem is that they get beat up pretty well with traffic loads and snow plows (remember when it used to snow?), and maintenance can get away from you. A smart strategy is to work in a line item in the budget for maintenance of signs, pavement markings, tubular markers, and other devices so that you have allocations each year and get out ahead of them before they are ineffective.
Highway or street lighting is a broad topic, but simply put, lighting should be thoughtfully designed to provide the correct illumination where it is needed, without creating glares issues. In municipal areas, it is often desired that street lighting be aesthetically pleasing, and they can be effective without compromising the look and feel. Good lighting vendors will respond well to this “dual mandate” and provide options that don’t force you to sacrifice one need for the other.
Signs, of course, are part of the nighttime visibility solution set, and so they must also be in good condition. Retroreflectivity is required of most signs and there are several ways to manage good retroreflectivity throughout the service life of signs.
Dedicated bike lanes have become increasingly used, but they often rely on pavement markings and here also, they are not a “set it and forget it” measure. For cyclists to be comfortable using bike lanes, the pavement markings and signs must be as well maintained as the rest of the roadway system.
Perhaps one of the most commonly overlooked pavement markings is the crosswalk, followed closely by the stop bar. When we have determined that these markings are important for public safety, the pedestrian comes to rely upon them. But they can become a false sense of security when they wear away and approaching drivers can no longer see them in time and they fail to elevate awareness for the driver. It is important to project the useful life of pavement markings (which can vary with the product and type of application, among other factors) and program in their replacement so that they are “on the calendar” and, as importantly, in the budget.
Our September 2022 e-newsletter included a moderately brilliant overview of pavement marking types and materials that may be useful if you are re-evaluating your markings placement and maintenance strategy.
So while you’re at that quiet time of year where nothing much is going on and you have lots of free time, maybe take some time out to look at key areas of your streets, intersections, and crosswalks to see what vulnerabilities may exist and how you can beef those areas up with better long-term maintenance strategies and even a capital project.
The Delaware T2/LTAP Center’s Municipal Engineering Circuit Rider is intended to provide technical assistance and training to local agencies and so if you have nighttime visibility concerns or other transportation issues, contact Matt Carter at matheu@udel.edu or (302) 831-7236.
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