Safety: The Other Side
 of Highway Beautification

Without careful planning, landscape design can create worker hazards.

by David R. Warren

A failure or a success in a landscape is in the design. Eighty-five percent of the time this is true. While roadside beautification sounds good, our maintenance workers deserve a place to work where they don’t have to risk their lives to turn on the water or change out a sprinkler.

Are plants needed in this island?  They are difficult to irrigate and not particularly attractive.

Design concepts

We used to design landscape with a green blanket of ground cover from asphalt to asphalt. Entire interchanges, usually from 20 to 28 acres, were designed using this approach.

With water conservation issues in California and other states, safety issues, cost constraints, and other factors, our new landscape designs are becoming more functional and natural. Less irrigation, drought-resistant plants, less acreage planted, use of mulch, and so on are now common features of landscape design.

This is a good approach from a safety standpoint. Less can be better. Ease of maintenance must be considered in each design. We are now using radio-controlled remote control valves and irrigation consoles that look like a main telephone trunk line. The landscape designers know and understand how the irrigation system works, but how many maintenance workers do?

Valve manifold placement

Most RCV placement is for economy. That’s why we see two to eight (or more) valve manifold sets. For safety’s sake, never place these manifold sets near the road edge. Never place them on the left side of a right curve or the right side of a left curve. Why? Because we understand what Newton meant about centrifugal force and how errant vehicles will tend to miss the turn and go straight. If our worker is there, he or she may get run over. When RCVs are placed too close to the road edge, run-overs occur.

Digging out a valve manifold set and replacing the crushed main PVC line will take one or two days. So we need to think about where we place our RCVs.

Mass landscape plantings

An interchange or ramp where a mass planting is located usually invites the homeless. With this come needles, human waste, filthy living conditions, and in some cases, diseases. Maintenance workers need to clean up these sites.

A design concept that can be substituted is to plant low-growing shrubs or trees that are spread out.

Female employees reluctantly go into these mass plantings to repair sprinklers or prune. Mass plantings in urban areas need to be evaluated and perhaps reduced.

Sound walls

When a sound wall is placed in an urban area, a couple of things happen. First, a trail is created on either side of the wall. Yes, people or kids will walk these walls, using them as shortcuts to their homes or just a place to hang out.

If irrigation is placed adjacent to the walls, expect vandalism or theft. It is bound to happen.

Sound walls also become the canvas of taggers (urban painters). Matching the color and painting these walls is time consuming and expensive.

From a safety standpoint, try to avoid irrigation next to a sound wall. Employees could fall on wet, slippery ground. Risers/sprinklers should be inside or near the base of plants, rather than exposed next to walls for the vandals and thieves. For ease of maintenance and less exposure to traffic, place gates/doors in the walls every block.

Plant placement

We continue to see a line of planting material on dangerous gore points or connector ramps. Designers could walk these areas prior to drawing the plans to check on the propriety of sticking a line of shrubs on narrow areas of the highway. This is one of the most dangerous areas for workers to maintain. Many of these narrow areas are subject to run-overs where the plants eventually die and the irrigation is torn up.

Another area of concern is site clearance. Are plants too close to off/on ramp entrances/exits? Are trees/shrubs interfering with signs and fences? Are trees too close to traffic on an off ramp?

Plant placement provides another problem.  When trees are too near off/on ramp entrances as in these photos, they interfere with signs and fences, and are too close to traffic, the result may not be pretty.

Clean water source

Using clean water makes a difference in the levels of maintenance. Using well water or water that has been filtered with a sand trap will cause problems for the RCVs. In many RCVs, a couple of grains of sand in the small tubes or solenoids will cause a failure.

Clean water is essential for good irrigation in most cases. It also reduces valve/solenoid replacements, thus reducing employee exposure to traffic and reduction of costs.

Think before planning

When it comes to roadside design application, place yourself on site. Would you or your children like to maintain what you have just designed? Is the location too dangerous to maintain?

If not, then a cobble rock hardscape might be more suitable than landscape.

Think about who will maintain your landscape as well as who will enjoy it. Will that maintenance worker understand the radio-controlled and computer-operated irrigation system? Are we putting our workers in harms way by planting a narrow gore?

Have a maintenance supervisor review the preliminary drawings for possible areas of design change. Remember, people have to maintain what’s planted. Let’s minimize the risks for our maintenance workers by considering safety in our designs.

Reprinted from Better Roads Magazine
November 2002

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