Cornell Local Roads Program

Basic Roadway Improvements for Bicyclists

Looking for some simple ways to improve bicycling in your community? There are many inexpensive roadway improvements that can help ease conflicts and congestion for cars, bikes and even pedestrians. With the price of gas soaring, more and more people are taking to their bike or their feet for their shorter trips. Here are some suggestions to make the roads they travel on safer:

Patch and sweep carefully

Bicycles and bicyclists tend to be particularly sensitive to maintenance problems. Potholes that motorists would hardly notice can cause serious problems for bicyclists. In addition, since bicyclists ride near the right margin of the road, they use areas that are generally less well maintained than the main lanes. On higher speed roads, the passage of motor vehicle traffic tends to sweep debris to the right, where most bicyclists travel. Ridges, like those found where a new asphalt overlay does not quite cover the older roadway surface, can cause a bicyclist to lose control.

Example of a grate dangerous to cyclists

Aside from these general problems, special bicycle facilities often need more maintenance than they receive. Bicycle parking devices are particularly susceptible to misuse or neglect. On trail systems, for example, vegetation is often allowed to overgrow the pavement edge, effectively narrowing the usable surface. Soil treatments that are commonly used under new roadbeds are sometimes ignored on trail projects. As a result, the surfaces are quickly damaged by intruding plants.

For the most part, satisfying bicycling maintenance requirements is a matter of slightly modifying current procedures. If street sweeping crews pay a bit more attention to the right edge of the road, it can benefit bicyclists greatly.

Using maintenance friendly design and construction techniques can reduce the need for special and some-times costly treatments later. For example, when paving a street bordered by unpaved alleys and driveways, paving into those alleys and driveways 10 to 20 feet (depending on grades and other features) can keep gravel and other debris from being dragged onto the street by entering vehicles.

Finally, special bicycle facilities like bike lanes or trails may require enhanced maintenance attention. This cost, along with a clear understanding of who has responsibility for maintenance, should be part of every project budget.

You can maintain roadways and bikeways to a relatively hazard-free standard by:

Fix or replace dangerous drain grates

Drainage grates and utility covers can cause serious problems for bicyclists in several ways. Raised or sunken grates or covers can stop or divert a cyclist's front wheel, causing wheel damage and/or a serious crash. Old style parallel bar drainage grates can trap the front wheel of a bicycle, causing the bicyclist to be pitched over the handlebars.

Grates or covers that are not level with the roadway surface can be made less hazardous by raising or lowering, depending on the situation. During new construction the problem can be reduced through careful placement of utilities. By keeping these hazards out of bicyclists' most common path of travel on the right side of the roadway, problems can be reduced in frequency, if not in severity.

Parallel bar drain grates can be replaced with modern bicycle-safe and hydraulically efficient models, such as vane or honeycomb grates. When it is possible to do more than simply replace a grate, installing curb face inlets can move the hazard out of the roadway entirely. Inlets must be designed carefully to minimize cross slopes, which can throw bicyclists toward the curb.

There are two primary approaches necessary when addressing drainage grate and utility cover problems. First, existing problem locations must be identified and corrected according to a well-welldeveloped and prioritized plan of action. Second, design standards must be modified, as needed, to keep similar problems from arising in the future. It is far more cost effective to design with bicyclists in mind than to retrofit solutions later.

Winter 2006

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This work by the Cornell Local Roads Program (CLRP) is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.