by Fred Oswald, PE, LCI #947

This article illustrates typical cycling road hazards and measures a community can take to correct the hazards and improve conditions.  Keywords: Cyclist friendly, Bicycle friendly, Bike safety, Road hazards.

The most important measure a community can take to improve the cycling environment is to teach people how to drive a bicycle.  Most of the problems illustrated here are exacerbated by common mistakes made by people who do not understand the best practices of cycling.  Sometimes a well-chosen sign can help prevent mistakes and overcome misinformation.  For example, the sign in the photo at right says that bikes (actually cyclists) can use a full lane and faster drivers must change lanes to pass.

It is also important to fix problems that can contribute to crashes.  The most common accidents to cyclists are falls.  This is because bicycles are balanced vehicles with hard, narrow tires and (usually) no springs.  Some of these falls cause serious injuries, including fatalities.

Road defects often cause bicycle crashes.  A bump gives the cyclist an uncomfortable jolt.  A large bump can cause tire and/or rim damage and can cause a crash if the cyclist loses control or swerves to avoid the bump.  A deep chuckhole creates a severe jolt and can cause a stopping fall where the wheel stops suddenly while momentum carries the cyclist over the handlebars.  Small defects such as ridges and slots nearly parallel to the direction of travel can cause the front wheel to steer to the side or it can prevent steering required for balance.  This causes a diversion fall.  In addition, gravel or other slippery surfaces can cause skidding falls.  Besides direct injuries from impact with the ground, falling in front of a vehicle is likely fatal.


Cracks and Slots often cause diversion falls.  These gaps are prevalent in older concrete roads, especially in the joints between sections of concrete.  The left photo shows a wheel in a water-filled gap near a sewer grate.  There was a separate "pour" of concrete around the sewer catch basin to make sewer repairs easier.  This adds a seam thqat can produce a dangerous gap right where cyclists ride.

This photo was included on a one-page report of road defects the author gave to the Service Director of Middleburg Hts, Ohio.  The very next day, the supervisor of the city's road repair crew called to discuss the problem.  Since most city officials (like most citizens) are not experienced cyclists, they do not recognize problems such as this unless someone tells them about it.

The right photo shows temporary patching applied that same day.  The white paint marks where more permanent repairs will be made when schedule and budget permit.  We have also met to discuss other problem areas and how the city can reduce hazards.  This is an excellent example of a responsible government responding to a problem.  (Location: Bagley Road at Century Oak Rd.)


Parallel Bar Sewer Grates are extremely dangerous for cyclists.  A wheel can easily get trapped between the bars, causing a stopping fall which will pitch the cyclist on his head.  If the wheel does not slip in far, it may still be prevented from steering.  This will cause a diversion fall.

Another problem occurs when a grate is not level with the surrounding pavement.  Even a "bike safe" design can cause a crash if it becomes part of a "chuckhole".  The top photo at right shows a dangerous grate that is also mounted a little too low.  Notice how the wheel is in the slot up to the spokes.  (Location: E. Bridge St, Berea.  This defect should be reported to the city.)

Normally, an experienced cyclist will be at least 2-4 feet from the curb, outside of the grate area.  However, novices often ride too close to the road edge and in an emergency, even an expert may ride there.


The left photo shows a dangerous grate in a very bad location -- out in the roadway and just after a curve.  Although cross bars had been welded across the openings, both of these were partly torn away (likely by snowplows).

The right photo shows a much better grate installed just a few days after the author notified the Service Department of Brook Park, Ohio.  This is another good example of a responsible city government in action.  (Location: Switzer & Lucille Rd.)

Roadway Shoulders are a popular place for touring cyclists riding in the country.  But in an urban area, the shoulder is often NOT a safe place to ride.  A shoulder cyclist is much more likely to suffer a collision with turning traffic because other drivers do not look for conflicting traffic off the roadway.  In addition, the shoulder is likely to accumulate glass, gravel and other debris because passing traffic does not "sweep" it clean.  For these reasons, experienced cyclists avoid shoulders on urban roads.


A small shoulder protects the edge of the pavement from being broken by keeping heavy wheels nearer the middle of the road where the pavement is better supported.  One foot is enough shoulder space for this benefit.

In the photo at right, the travel lane is of marginal width to allow faster traffic to pass a bicycle.  The four feet of pavement in the shoulder is largely wasted as far as cycling is concerned.  If the fog line were moved over about three feet (indicated by dashed line), then the lane would be wide enough to share with faster traffic.  The remaining shoulder would be enough to protect the edge of the pavement.  (Location: W. 130 St, S of Bagley)

Difficult Spots for cyclists include narrow 2-lane roads with heavy traffic, narrow bridges, and "pinch points" in the roadway.  Since these problems are generally built in to the infrastructure, it can be difficult and expensive to cure them.  Often the best you can do is to teach people how to deal with the problem and perhaps erect a warning sign.


The photo at right illustrates a diagonal railroad crossing complicated by a grade that blocks sight of approaching traffic.  The cyclist must cross the tracks at nearly a right angle to avoid getting the front wheel caught in the groove next to the rails and then a diversion fall. That means veering to the left. Cyclists must be taught how to do this safely. Motorists must be taught that it is unsafe to pass at a place such as this.  (Location: Smith Rd. near Sheldon)

Sidewalks are designed for pedestrian use.  Many people think a person on a bicycle is some kind of pedestrian.  Wrong!  A bike can easily go 4 or 5 times as fast as a person walking.  And even faster downhill.  A bike cannot stop in a stride; it has brakes like other vehicles.  It cannot turn in place or step sideways like a pedestrian either.  These are a few of many reasons why riding on sidewalks is much more dangerous than driving on the roadway.  And why mixing cyclists and pedestrians is dangerous for both.


Those who ride on sidewalks face the risk of collisions at every intersection and even at driveways.  Other drivers do not look for conflicting traffic in unusual locations, such as on a sidewalk.

Sidewalks often have specific hazards, in addition to being inherently unsuitable for vehicular traffic.  The hazards include rough surfaces, sidewalk "furniture" such as utility poles and mail boxes, and poor sight lines due to vegetation, fences, etc.  The photo at right shows an untrimmed hedge blocking the view from a commercial driveway.  (Location: Smith Rd. exit of Ganley auto dealership)

Appropriate Facilities do not subject cyclists to unforeseen hazards by forcing them to violate the rules of the road.  A bicycle "sidepath" is really just an asphalt sidewalk and it has nearly all of the dangers.  Recreational paths are often popular.  They can be reasonably safe only for slow speed use if designed properly.


A shortcut path linking places that are otherwise not connected can be very useful for transportation.  The photo at right shows a road barricaded to prevent cut-through traffic.  A short path would restore this road as a bicycle corridor without compromising the "traffic calming" purpose of the barricade.  (Location: S. Rocky River Dr, Berea)

The best bicycle facility is a well-designed and maintained road. A little extra space in the right lane (called a wide outside lane) helps faster traffic pass bicycles and this reduces friction between road users.

Parking is nearly as important for cyclists as for motorists.  Bicycles take little room and can often be locked to a fence, sign, etc.  Traditional school yard "wheel bender" bike racks are not suitable for good bicycles with expensive aluminum wheels.  unfortunately, some bike racks are even worse than the old schoolyard racks.


Often an informal parking spot (locking to a signpost or fence, etc.) is the best choice.  Appropriately, the sign below the parking meter at right says "small vehicles only".  Unfortunately, some communities make locking to parking meters illegal.  We have even heard of local ordinances requiring use of a bike rack, where provided.  They make no allowance for the risk that a bad rack can damage a good bicycle.

Other Issues:  Important tasks include teaching people the best practices of safe and effective bicycle operation, passing equitable laws, training police and making vehicle detectors work with bicycles.  These are covered in the Ohio Bicycle Federation's Cyclist Friendly Communities Program 'Toolkit'.  For more information on planning for bicycle transportation, see Bicycle Transportation Policy Statement from the Ohio Bicycle Federation. 

We suggest that transportation officials and planners read the book Bicycle Transportation, by John Forester, MIT Press, 1994.  It will take some effort to get past the bitter, confrontational style of the author but once this is done, you can learn from a real expert.


[1] Alan Forkosh photo.

© Copyright 2003-2008 Fred Oswald and Ohio Bicycle Federation.  Material may be copied with attribution.
The author is a certified "League Cycling Instructor", and a professional engineer in Ohio.
Last Revised 6/25/08  Check for updates at