Multi-lane Roads

Long-distance communication: Let them know what they need to do before they get to you.

I bet you never thought multi-lane roads were safe, low-stress places to ride. This video will show you why some of us prefer them to two-lane roads. Set it and forget it. It’s all about work load.


Topic 3: Multi-lane Roads

Topic Introduction

We’ve spent a lot of time discussing strategies to help motorists get around us on two-lane roads. Multi-lane roads may seem intimidating to cyclists, but they require a lot less work and often offer a safe, low-stress option. But there are a few key differences for determining the best lane position.

Basic Dynamics

Where there are passing lanes, the bicyclist does not need to worry about sight lines, intersection conflicts or facilitating the pass. The bicyclist’s only objective is maximizing her safety.

Because the conflicts are behind the motorist who wants to pass, he must look back to change lanes. Because of this, lane changes are easiest when the motorist is traveling at the speed of traffic in adjacent lanes.

Influencing Passing Behavior

So the behavior we want to influence is early full lane changes.

We do that with a lane position that communicates clearly from a distance that a lane change is required.

Let’s look at how position influences full lane changes and why full lane changes are critical.

In a study conducted in Southern California, researchers rode multiple passes on same stretch of a six-lane arterial. On each pass, they moved farther out from curb and then measured the passing clearance.

Here is what they found:

Initially, the passes got closer as they moved into the lane. This is because motorists were staying in the lane. The cyclists were decreasing their distance from the passing cars.

The worst pass occurred when a motorist passing in lane with the cyclists was being passed by a tractor trailer in next lane.

Once they got out about three feet from the curb, passing clearance began to increase because motorists were moving partially into the next lane.

Once they moved to the center of the lane, all passes were full lane change. Between the center of the lane and the left tire track, the researchers found the sweet spot — the best, consistent passing clearance along with full lane changes from all drivers.

The Problem With Partial Lane Changes

If passing clearance was the only issue, the partial lane changes would be good enough. Unfortunately, there’s a safety issue with partial lane changes, so we want to discourage them.

A partial lane change usually starts with a motorist not recognizing the need to change lanes until it’s too lane. The cyclist may be far enough into the lane that, up close, it’s obvious the lane can’t be shared. But from a distance it is not.

The motorist then faces a dilemma. He should slow down and carefully check behind him for overtaking traffic, waiting until it’s safe to change lanes. But once he slows down, it’s harder to change lanes.

This is why many motorists will opt for a partial lane change at speed. Because the cyclist still has a fair amount of space to her left, the motorist is encouraged to use some of it while cheating into a gap between cars in the next lane.

Unlike a full lane change, which requires more diligence in checking for traffic in the next lane, a partial lane change is prone to errors in perception and judgment. As a result, partial lane changes increase the likelihood of buzz passes and risk for sideswipe crashes.

When you see motorists making partial lane changes, that’s an indicator you need to move a bit farther left to get to the sweet spot.

When motorists can tell from a distance they need to change lanes, traffic will flow around you much more easily.

You can’t completely eliminate late lane changes. There will always be drivers who, for whatever reason, get stuck behind you for a few seconds. Optimal lane position does reduce it significantly. But more importantly, even those who wait too long will make complete lane changes.

Early Lane Changes Lead to More Civility

The study I discussed earlier was a game-changer for many of us. It was the information that inspired us to try lane control on high-speed arterial roads. The thing that amazed me most when I tried it was not the lane changes — I expected that — it was the decrease in honking. Yes, I said decrease!

After evaluating hours of video, Keri & I guessed that the improved civility was a result of the early lane changes. Most motorists were changing lanes so far back — and without even taking a foot off the gas — that they were not inconvenienced.

Could it be that rather than being provocative, we were actually doing them a favor?

Keri and I decided to explore this from the motorist’s perspective. The video and write-up from that experiment are linked in the resource section below. As is the Southern California study.

Lesson Conclusion

In this lesson we’ve discussed how our lane position influences passing behavior. In the next lesson we’ll learn about direct communication, Jedi mind tricks, and other ways to get what you want in the car-centric world.


Study: Bicyclist Roadway Position versus Motorist Passing Distance – Southern California study of how lane position influences passing clearance.

Helping Motorists with Lane Positioning – Closer look at why assertive lane position results in better passing and less honking.