Close and fast passing of cyclists by motorists can be dangerous. Cyclists can fall, swerve or suddenly leave their path at almost any time, because of losing their balance (usually only when moving slowly uphill), but mostly in order to avoid some kind of unexpected obstacle (like a piece of debris, or a hole or crack in the road).

In any case, if a motorist happens to be closely passing a cyclist right before he or she swerves or falls to the left, the results can be catastrophic. So, it's helpful to know what to do to discourage close passing, and to encourage motorists to slow down as they pass.

Bike lanes don't help, and actually often exacerbate the situation, by giving the passing motorist a false sense of confidence that the cyclist will stay in his lane, thus alleviating him from feeling the need to slow down and/or move left.

In another thread, the contention was made that motorists don't slow down for anything these days. I disagreed, because they slow down for me, after I learned how to get them to slow down.

One of the surprise side benefits of using a mirror is learning how to control passing motorists in terms of slowing them down and getting them to move left.

Tools that I use to slow motorists down and get them to move left include:

• My own lane position. The closer I am to the curb, the closer they tend to buzz by me. As I move out away from the curb, they tend to slow down and move further left. Sometimes I have to move to the center of the lane (between the left and right tire tracks) to "take the lane".
  
  But this never works in a bike lane. They don't seem to be affected by my position at all, or even my presence at all, when I'm in a bike lane. They just blow by me as if I'm not there, unless I do something like...
• Zig-zags. When I'm in a bike lane, and see passing traffic coming in my mirror too fast and/or too close to me, I do some zig-zags. Works like a charm! They SLOW DOWN and MOVE LEFT. I don't care if they think I'm an unpredictable lunatic on a bicycle, as long as they pass me with a reasonably safe passing margin.
• Ride outside of the bike lane. Two inches to the right of the stripe, and they pass me like I'm not even there... (no slowing down or moving left). If I move two inches to the left of the stripe, the effect is remarkable. You can feel how they instantly become aware of you, and you can see it in your mirror: they SLOW DOWN, and MOVE LEFT. (bonus: less debris and fewer flats when riding to the left of the stripe...). Couple this with the next tip and you're golden...
• Issue the "slow/stop" signal (left arm out and down). This gets their attention almost every time. Sometimes I forget to do it, have motorists passing me unsafely fast and close, whip out the sign, and they instantly slow and move over. It's great!
• Stand up and throw the bike right and left in an exaggerated manner. Similar effect to the zig-zag trick, but generally only useful on climbs.

Anyone else got any other tips? What do you do to cause motorists to slow down and move left as they pass you?