ARTICLE: Cyclist Errors which Cause Automobile-Bicycle Collisions, Illustrated

Cyclist Errors Which Cause Automobile-Bicycle Collisions, Illustrated

Most collisions between bicycles and motor vehicles don't happen just by chance; instead, they are bought about by a misunderstanding of how traffic works. This page focuses on dangerous traffic situations which could result in collisions, injuries, and even death due to the fault of the bike rider. Another page looks at the kinds of accidents caused by motorists. I also have a page discussing all the types of bicycle-motor vehicle crashes and another page discussing how to ride safely in traffic. At the bottom of this page are links to illustrated pages elsewhere. On this page, I will 1) explain which cycling behaviors are unsafe, 2) provide diagrams to show various situations in which the cyclist endangers himself or herself, 3) explain what is happening in the diagram and why the behavior is unsafe, and 4) provide a safer alternative.

Here are some of the errors that bike riders frequently commit which greatly increase the chances of a collision with a motor vehicle:

1. They do not follow the traffic laws for vehicles when operating a bicycle. Instead,
    a) they may use the traffic laws for pedestrians and thus ride on the sidewalks or the wrong way on the streets,
    b) they may follow the traffic code for vehicles part of the time but not all of the time,
    c) they may adopt a policy of hiding from motor vehicles rather than riding in the traffic lanes,
    d) they may be guerilla cyclists deliberately breaking the law,
    e) or they just might not think about how they are behaving.
2. They don't have lights mounted on their bikes when riding at night.
3. They ride along in the gutter or weave in and out between cars.
4. They don't pay attention to nearby vehicles.
5. They haven't learned how to control their bicycles effectively.
6. They panic when motor vehicles approach.
7. They don't keep the bike in sound mechanical condition.
8. They ride when too tired (or even drunk) to do so safely.

While there are both dangerous and clueless motorists, the vast majority have no desire to harm cyclists and attempt to drive safely and appropriately when cyclists are around. Motorists nearly always obey the traffic code, except for driving too fast, and they usually will cooperate with the cyclist.

A study of the following common accidents will indicate the kinds of problems that cyclists can get into who don't follow the traffic code for vehicles.

An Explanation of the Details of the Following Diagrams

A. Curb or road edge, a thick black line.
B. The cyclist.
C. Path cyclist will follow, in black.
D. Moving car or vehicle.
E. Path moving vehicle will follow, in blue.
F. Parked car next to curb, no arrow, hence not moving.
G. Sidewalk.
H. Crosswalk.
I. Car or other vehicle in driveway.
J. Path vehicle will follow, indicating a stop.
K. Grass, trees, waste land, buildings, whatever.
L. Car stopped at intersection; no arrow, not next to curb.
NOTE: Distances have been compressed.
NOTE: The diagrams often include just half of the street.
NOTE: Arrows indicate vehicle movement only.
NOTE: Any vehicle without an arrow is stopped.

The Group IA Type Collision

This kind of collision involves the cyclist entering the roadway from a driveway or a sidewalk without stopping. About 12.5% of all car-bike collisions (based on data from the Carol Tan study) are of this kind.

Being Struck by a Vehicle While Entering the Roadway from a Driveway

SITUATION: A cyclist is leaving a driveway, fails to stop, and is hit by a motor vehicle. This kind of collision is 7.4% of the total with about 23% of these accidents causing serious injuries or death. Most of the bike riders involved were under fourteen.

HOW TO AVOID: Whenever a cyclist arrives at a major roadway from an alleyway or drive or whenever the cyclist starts out onto the roadway, the cyclist should carefully scan in both directions to be sure that no vehicle is approaching. If visibility is blocked, the cyclist should ease forward until able to see or should enter the roadway at another point.

Being Struck by a Vehicle While Entering the Roadway from a Sidewalk

SITUATION: A cyclist is riding along a sidewalk and swerves over to the roadway, where the cyclist is struck by a motor vehicle. About 4.4% of the collisions were of this type, with 20% causing severe injury or death. About 70% of the cyclists were under 14, and 45% of the adults were drunk.

HOW TO AVOID: A cyclist should always stop and look before entering the roadway and wait for any motor vehicles to pass.

Being Struck by a Vehicle While Entering the Roadway from a Sidewalk via a Driveway

SITUATION: A cyclist is riding along a sidewalk and swerves over to the roadway via a driveway, and is struck by a car or other motor vehicle. This was just .7% of all the accidents with 18% resulting in a serious injury or a fatality; in about 70% of the cases, the cyclist was traveling the wrong way. About 90% of the cyclists were under 19.

HOW TO AVOID: A cyclist should always stop and look before entering the roadway and wait for any motor vehicles to pass. A cyclist should not ride against traffic in the street.

The Group IB Type Collision

Most Type IB collisions involve a motorist pulling onto the roadway from a driveway, parking lot, or parking space. They are generally caused by the motorist; however, the cyclist can contribute by traveling in the wrong direction on the sidewalk or street, as the motorist does not scan in that direction. Some 6.9% of all bike-car collisions happened with the motorist pulling out forward, but 20% of time, the cyclist was on the sidewalk and about 2/3rds of the time, the cyclist was traveling the wrong way on the road. Most of these accidents happened to adults.

Being Struck on the Street by a Vehicle Which is Leaving a Driveway

SITUATION: A motorist pulling out of a driveway fails to see a cyclist traveling the wrong way on the street because the motorist is watching for traffic coming from the other direction.

HOW TO AVOID: Don't expect motorists to see you when you are coming from the wrong direction. Ride in the same direction as traffic instead.

Being Struck on the Sidewalk by a Vehicle Which is Leaving a Driveway

SITUATION: A motorist is pulling out of a driveway and fails to see a cyclist traveling the wrong way on a sidewalk because the motorist is looking for vehicles coming from the correct direction.

HOW TO AVOID: Don't ride on sidewalks. Don't ride on the left side of the road whether on the roadway, a bikepath, a bike lane, or a shoulder, as motorists don't look for vehicles coming from the wrong direction.

Group IIA Type Collisions

These collisions or potential collisions involve the cyclist's failing to stop at an intersection, either at a stop sign or flashing red light (9.7% of collisions, of which 23% resulted in severe or fatal injuries) or at a traffic light with a traffic light or no signal (7.1% of collisions of which 16% were severe or fatal). More than half of the riders were under 14.

Getting Hit Due to Failure to Yield at an Intersection

SITUATION: The cyclist arrives at a stop sign, flashing red light, red light, or intersection with a larger road which lacks a sign, rides through without stopping, and thus gets hit by a motor vehicle.

HOW TO AVOID: Whenever you approach an intersection, pay attention to traffic lights and signs. If there is a yellow light, red light, or flashing red light, come to a full stop. With a stop sign, it is OK in most jurisdictions to stay in the saddle provided you slow nearly to a stop, look carefully both ways, and proceed only if clear. If there is no signal or sign and you are crossing a larger road, be suspicious enough to look to see if there are stop signs for those coming on the other road. If not or in doubt, yield to motor vehicles coming along the other road. In fact, it is a good policy to watch motor vehicles even when you have the right-of-way.

Group IIC Type Collisions

These collisions involve the cyclist making a turn, usually not at an intersection. They total 6.5% of bicycle crashes.

The Cyclist Makes a Left Turn in Front of a Vehicle Traveling in the Same Direction

SITUATION: The cyclist, beginning a left turn, swerves out in front of a vehicle traveling in the same direction. About 4.3% of bicycle-motor vehicle collisions were of this type, and 28% were severe or fatal. Nearly half of these accidents happened to children under 14.

HOW TO AVOID: There are several ways to safely make a left turn. When traffic is not too heavy, the best method is to make the same left turn as the other vehicles make. Look behind to make sure the road is clear, then move over to the left-turn lane (or the left portion of the center lane, if there is no left-turn lane) before making the turn. If traffic is too heavy to allow you to do so, you could also dismount, walk across on a crosswalk, and remount on the road on the other side.

The Wrong Way Cyclist Makes a Right Turn in Front of a Vehicle Traveling in the Same Direction

SITUATION: The cyclist, traveling on the wrong side of the road, and beginning a right turn, swerves out in front of a vehicle traveling in the same direction. About 1.4% of bicycle-motor vehicle collisions were of this type, and 27% were severe or fatal. Almost 2/3rds of these accidents happened to children under 14.

HOW TO AVOID: Never ride on the wrong side of the road. Never turn without scanning for traffic.

The Cyclist Makes a Left Turn in Front of a Vehicle Traveling in the Opposite Direction

SITUATION: The cyclist, beginning a left turn, swerves out in front of a vehicle traveling in the opposite direction. About .8% of bicycle-motor vehicle collisions were of this type, and 26% were severe or fatal. Most of these collisions happened to small children.

HOW TO AVOID: The vehicle traveling straight through the intersection has the right-of-way. Watch for on-coming traffic before turning left.

Group IID Type Collisions

This kind of collision involves a turning motorist. Usually, these accidents are the fault of the motorist, as the turning vehicle must yield to vehicles traveling straight; however, in five of these kinds of collisions, the cyclist was on a sidewalk, passing on the wrong side, or traveling the wrong way.

A Right-Turning Motorist Hits a Wrong-Way Cyclist

SITUATION: In the diagram, the motorist can't see the cyclist due to a parked car between them. The cyclist could be coming from the street the motorist is turning onto or could be coming from straight ahead. The motorist, in making a right turn, scans for vehicles coming from the correct direction but is unlikely to look for a wrong-way cyclist. A cyclist traveling the wrong way on the street that the motorist is turning right onto is very unlikely to be seen by the motorist in time even if there is no parked car because the motorist will have his attention focused on the opposite traffic lane.

HOW TO AVOID: Travel with traffic, not in the opposite direction.

A Right-Turning Motorist Hits a Cyclist on the Crosswalk

SITUATION: In the diagram, the motorist, making a right turn, fails to see a cyclist moving onto the crosswalk due to a parked car. There are other problems as well, even when there is no parked car. The motorist is not expecting a quickly moving cyclist to cross the crosswalk, nor can the motorist see the cyclist very well, especially if the cyclist is moving faster than the motorist.

HOW TO AVOID: Never ride across a street on a crosswalk. Turning motorists can not see you, and you can not maneuver quickly enough to avoid being hit.

A Right-Turning Motorist Hits a Cyclist Passing on the Right

SITUATION: The motorist, making a right turn, fails to see a cyclist who is attempting to pass on the right side. (The other automobile is waiting for the light to change.)

HOW TO AVOID: Use extreme caution if passing motor vehicles on the right, even if traveling in a bike lane. Many motorists have no mirrors on the right, and none are expecting to be passed on the wrong side. Never pass a slowly moving motor vehicle on the right at an intersection unless you are certain that it is turning left.

A Left-Turning Motorist Hits a Cyclist Traveling the Wrong Way

SITUATION: The motorist, making a left turn, fails to see a wrong-way cyclist either on the street the motorist is turning into or riding parallel. The motorist is worried about motor vehicles coming in the correct direction and thus is less likely to notice a wrong-way cyclist in the street. The cyclist traveling parallel might be moving faster than the motor vehicle and thus not be visible until the last second.

HOW TO AVOID: Travel with traffic, not in the opposite direction.

A Left-Turning Motorist Hits a Cyclist Traveling the Wrong Way on a Crosswalk

SITUATION: The motorist, making a left turn, fails to see a wrong-way cyclist on the sidewalk beginning to cross on the crosswalk. The cyclist might be partially hidden from the motorist, but in any case, the motorist scans for slowly moving pedestrians, not rapidly moving cyclists. Crossing a crosswalk in the wrong direction significantly increases the danger.

HOW TO AVOID: Travel with traffic, not in the opposite direction. It's best to never travel on a sidewalk, but even more important, never ride across a street on a crosswalk.

Group IIIA Type Collisions

These collisions are caused by faulty control on the part of the cyclist or motorist. When the cyclist is involved, the bicycle might swerve into the path of the motor vehicle. Or the cyclist might run into the back of a parked, stopped, or slow-moving motor vehicle.

A Cyclist Runs into the Back of a Stopped or Slow Moving Car

SITUATION: A cyclist is daydreaming while riding down the street and runs into the back of a parked car (1.4% of collisions, of which 10% were severe) or he runs into the back of a slow or stopped car (1.3% of collisions, of which 5% were severe).

HOW TO AVOID: Don't daydream while riding a bike, and pay attention to what is happening in front of you.

A Motorist Hits a Swerving Cyclist

SITUATION: The motorist is passing or approaching a cyclist who loses control and swerves into the path of the motor vehicle. NOTE: This type accident involves loss of control in any circumstances, and thus could be happening on a slippy curve or anywhere else. The cyclist might also run into a vehicle coming from the opposite direction. Accidents involving loss of control on the part of the cyclist constitute 1.2% of all collisions of which 33% were severe or fatal.

HOW TO AVOID: Don't ride so close to the edge of the road that you hit potholes or the edge of the pavement, which can throw you off of the bike or cause you to swerve. If traveling with another cyclist, keep enough distance so that your front tire does not hit the rear tire of the other bike, which will cause you to swerve violently. Don't travel around curves, especially when the pavement is wet, fast enough that you could lose control. Some cyclists swerve to the left when looking back, so either practice looking back while away from the road or use a rear view mirror. When a vehicle passes, don't swerve to the left without checking for following vehicles.

Group IIIB Type Collisions

This kind of collision involves a motorist passing a cyclist on a straightaway. Usually, these kinds of collisions are the fault of the motorist; however, the cyclist can be traveling at night without lights or can swerve into the path of the motorist.

A Motorist Hits a Difficult-to-See Cyclist

SITUATION: The motorist, traveling down the road, fails to see an unlit cyclist. Other factors are likely to be involved, such as a distracted motorist, a foggy windshield, a dip or bend in the road, or vehicles coming the other way. Speed makes a difference as well, as the motorist begins braking only after seeing the cyclist; thus the motorist could see the cyclist at the last instant but be unable to stop quick enough.

HOW TO AVOID: Travel at night on a bicycle only if you have both lights and reflectors, front and rear. Be especially careful at night and at other times of poor visibility, such as a low sun. If motor vehicles don't slow or move over, exit the roadway if necessary.

A Motorist Hits a Swerving Cyclist

SITUATION: In the diagram, the cyclist is swerving in and out among parked cars. As alternatives, the cyclist might swerve onto and off of the sidewalk or might swerve over to the crosswalk at an intersection and back into the traffic lane on the other side. Finally, the cyclist might swerve to avoid an object or hole in the road. The motorist sees the cyclist turn out of his path and thus does not slow down. A second later, the cyclist swerves back into his path.

HOW TO AVOID: Travel in a straight line without swerving. If you must move to the left, do so gradually and only after checking the vehicles approaching behind you. If you cannot pass an obstacle without swerving and a motor vehicle is right behind you, stop.

Group IIIC Type Collisions

These collisions involve either the cyclist or the motorist being on the wrong side of the road. It is rare for the motorist to be on the wrong side.

A Motorist Hits a Wrong-Way Cyclist

SITUATION: The motorist, traveling down the road, hits a cyclist traveling towards him in the same lane. See my article on Wrong Way Cycling to understand the many reasons why this kind of collision is much more likely than a collision while cycling in the correct direction. Note: This category is included as a separate accident type because many wrong-way collisions have no other causal factor; however, riding on the wrong side increases the chances of most kinds of collisions, as can be seen in the illustrations above. These collisions were 2.7% of the total, of which 32% were severe or fatal.

HOW TO AVOID: Ride on the right side of the road, following normal traffic flow.

There are four other sites on the web which also use graphic diagrams to illustrate car-bike collisions. Two are handbooks, John S. Allen's Street Smarts and Wayne Pein's Road Vogue, and two illustrate collision situations only, Michael Bluejay's How to Not Get Hit by Cars and Carol Tan's A Crash-Type Manual for Bicyclists, the last providing the statistics used here.

Continue to Mistakes Made by Motorists