GLC: Shoulders & Bike Lanes

Most bicycle-specific infrastructure is designed for individual users. Even when there are many, they are acting and making decisions as individuals. A group acting as a unit on a path or even in a bike lane is often challenging, and sometimes untenable. Let’s look at some of the issues and ways to compensate.

Shoulders & Bike Lanes


image of bike lane surface hazard problematic for group
By the time the front rider identifies a hazard, the group will be too close to alert the rear rider and accomplish a safe lane change. Sudden braking can cause a crash. And a rider hitting a surface hazard can cause a crash. There are no good options.

Shoulders and bike lanes can be problematic for groups. They both collect debris—AKA surface hazards. As we discussed in the previous lesson, lane changes must be made from the rear, but the rear rider can’t see surface hazards. Most surface hazards can’t even be identified by the front rider in time to communicate the need to change lanes.

Shoulders are often worse because they are not required to be maintained for vehicular use. They’re also often marginal with regular discontinuation at intersections.

The best solution is just to not ride in these spaces unless they are well-maintained and wide enough for the riders to avoid potential hazards without having to swerve into the adjacent lane. Also, smaller groups fare better in bike lanes than large ones.

Several states have laws requiring bike lane use. A couple states even require shoulder use. Check your state statutes.

Right Hook Conflicts

Motorists frequently misjudge the distance needed to pass a single bicyclist. A long group of riders presents an even greater challenge.

When traffic is flowing in the right lane it is very easy for motorists to discount potential conflicts with a group of cyclists. A motorist can begin passing the group hundreds of feet before an intended right turn, but due to the length and speed of the group he may reach his turn at the same time as the front rider. In the best case, he will have to stop in the right lane and wait for the group to pass. In the worst case, he may attempt to beat the group to the turn, but then cut them off as he has to slow to make the turn.

There are three countermeasures for this. The choice may depend on the type of group, the laws requiring bike lane use, or the frequency of intersections.

  1. If intersections are infrequent and the group is good at lane changes, the rear rider can initiate a lane change several hundred feet before the intersection and get the group out of the bike lane.
  2. With a social group, it’s sometimes too labor intensive to move the group in and out of a bike lane. So the rear rider can simply move out on the approach to an intersection and control the right lane to guard the flank.
  3. If bike lane use is not required or if intersections are so frequent that the group would be moving back and forth every 10 seconds (labor intensive and unpredictable!), the group should simply ride two abreast and control the right lane. Obviously, this will go over better on a multilane road where overtaking is easy.

The presence of a right turn lane does not eliminate the conflict when a passing motorist who wants to turn reaches that turn lane at the same time as the front rider. The group will form a wall between the right lane and the turn lane. Again, you have the potential for the motorist to race ahead and cut the group off.

illustration of pocket bike lane issues
The “Flotsam Jetty” is a patch of intersection debris (often broken glass) swept by vehicles on both sides of a bike lane.

Another adventure offered by this configuration is what we call a Flotsam Jetty. Cars in the through lane and the right turn lane sweep debris into the space directly ahead of the bike lane at the intersection. This area often contains broken glass and pieces of metal from car collisions, as well as sand and organic debris.

Sometimes It just better to get the group into the thru lane before reaching the start of the turn lane. Then just go back into the bike lane after the intersection.