vrkelley

While the cars are passing, turning or waiting for you...how do the drivers perceive your velocity? Is there a way to tell drivers your speed?

So...if you're spinning 120 RPMs...do they perseive that you're going faster? Without brake lights, how do they perceive that you are slowing?

tjspiel

There are hand signals for slowing down/braking though I doubt many drivers know them anyway. Other than that different drivers may use different cues to figure out how fast you're going just like they would another car.

Because you're on a bike, they may assume you're moving slower than you are.

Why do you ask?

Grim

No Doubt about that. The last two riders I heard about getting run down from behind locally were signaling to make lefts and the driver tried passing them on the left as they were turning claiming the rider told them to pass by pointing left.

vrkelley

The driver that Right Hooked me said she misjudged my speed. I was accelerating aggressively to begin an ascent. However, at the time she turned right into me, I was probably going about 15mph.

It's true, you can't fix Stupid, but you can proactively improve your odds if you understand 'Stupid' thinks.

EDITED: Re my original post, I was only beginning the climb @ about 75-80 RPMs.

vrkelley

Right, while turning left, the arm has to be straight out for about 100' before you actually turn (not always possible). No bobbing. Also you are looking in the direction that you turn so the driver can guess your intent

BMWdoc

I think lights are the most important ways to alert drivers. There is no real way to tell them your speed but I know for a fact that with lights on even in the daytime, drivers will wait before turning in front of you. Before I used bright lights they were more willing to turn at alot closer distances. Now from about 100 meters away they will refrain from turning or pulling out in front of me.

M. Rhoten

If I'm turning left, I don't lock my eyes left. They should be looking up front where the danger is. I do rotate my HEAD head left to help communicate to the car behind me that that's where I'm going.

Torrilin

When I drive a car (rare these days) I judge speed by how much the object changes in size over 2-3 brief glances. This actually gives me a speed *difference* between my vehicle and my sample object. Even now, after 5 years of being car-free, I am pretty accurate. A lot of that accuracy is due to hours of drill. I can still keep a car at 15 or 35 or 50 mph, without the help of a speedometer. It was something my parents insisted on as a basic driving skill that I had to have, before I was allowed to use cruise control. It takes a LOT of attention to do. (for me, it takes even more attention to drive with cruise control tho... so when I drive I do not use it)

Most drivers cannot do this kind of speed judging. This makes them very dangerous, because they have to spend much more time looking at the dash than at the road around them. Their speed is often erratic.

You don't really have a way to force other drivers to have skill and wisdom. It sucks. I don't drive partly because the lower the speed, the lower the stakes. I can't make everyone else be smart, but I can keep *my* speed down to something that is well within my abilities.

HardyWeinberg

I always think it's implicit that I'm going their speed if I'm in the lane. I think they perceive that as passive-aggressive obstruction.

mechBgon

I sometimes use body-language cues. If someone's driving towards me and planning to turn across my path, and I want to send a cue, I can either:

1) stop pedalling and coast (go ahead and make your turn, I'm coasting down), or

2) upshift and jump out of the saddle with a pronounced rocking of the bike (I just got bigger and I'm obviously accelerating, wait for me to go by). Rocking the bike also causes the bike's lights to weave, another attention-grabbing benefit (I run lights day or night).


If pedestrians step into the crosswalk while I'm being tailed by cars, I often use the SLOWING/STOPPING arm signal in conjunction with abruptly stopping pedalling, to jog peoples' attention and send both the legal and body-language signals that I'm slowing or stopping. My current commute takes me past our county courthouse, with tons of cars parking and embarking, as well as tons of pedestrians in crosswalks, so this can be necessary on any given day.

electrik

I don't tell them my speed. I assume drivers just figure it out the same way they judge how fast other cars are going. Which is to say, poorly.

I think cars should have speedometers in them, to judge speeds, even better they should have GIANT leds on the top expressing their speeds for the saftey of all nearby.

Tundra_Man 

My experience is that car drivers see a bike and just assume "slow." I see no real effort to estimate speed.

vrkelley

Sometimes cars pull wait and then pull right out in front to me--seeing but then misjudging my speed. Other times a car will ride along side me for several blocks presumably clocking my speed befor they actually pass and go on their way.

electrik

Yes, the longer a driver waits at an intersection the more likely they will be to perform a risky maneuver. Ergo, people feel they've waited too long for you and pull out at the very last second.

chipcom 

And don't point...pointing when signaling a turn can confuse drivers - are you going there or do you want me to go there? Keeping your palm open might help minimize that confusion.

As far as judging speed, you drive too, right? How well do you judge the speed of cyclists?
I think that ability is specific to the individual, some of us have no problem with it, others, not so much. IMO, my sense is that the woman you hooked you was blowing smoke either way...she didn't misjudge your speed, she expected YOU, the one riding the toy and getting in her way, to yield to her.

kmac27

Most motorists don't know that a bike can go much faster than 10 mph. Most are even shocked when I tell someone that I can average 20 mph on a short commute on my hybrid. Some drivers are pissed off when I keep up with them at 25 mph on the back roads. I've even had them brake agressivly because they didn't like me behind them.

Doohickie

Hand signal: Arm out, forearm pointed down, palm facing back.

fetad

I'm surprised this wasn't brought up yet.

Speedometer Vest

electrik

Depressing. As if hi-viz clothing wasn't already a badge of shame, now we have to have lights telling everybody around us out speed. Gee.

Bekologist

i wouldn't count on it, but steering directly towards the motorist with a 300 + lumen, flashing LED headlamp aimed at eye level is a good way to alert them of your presence in the lane, if nothing else.

won't really tell them your speed but it does give them a visible reference point that there's a vehicle approaching possessing a quite real presence on the road.

there seems to be fair compliance from motorist towards cyclists right of way reported by Northwest riders running daytime LED arrays, but of course this is never assured from a moronist. i mean a motorist.

whitecat

2x P7 MTE's pointed in their way at eye level, high mode(~400 lumens each). Grabs their attention real quick. If they fail to stop when I have right of way, and try to cut me off, I switch them to strobe mode. Never fails to stop them from cuting me off. Nothing like hi powered LED lights hehe.

HardyWeinberg

I'm guessing you were born before 1970.

(hey, me too, I'm just saying, holding up the rosetta stone and pointing to the 'stop' hieroglyph would be about as effective)

banerjek

Hold your hand down to signal a stop. Everyone seems to get it.

Drivers won't estimate your speed accurately, so don't even try. Your cadence and positioning will help them understand what you intend to do.

banerjek

Hold your hand down to signal a stop. Everyone seems to get it.

Drivers won't estimate your speed accurately, so don't even try. Your cadence and positioning will help them understand what you intend to do.

fat_bike_nut

Hey, I was born in 1984, and I use arm signals all the time whenever I ride. At least the motorists around here understand what an arm sticking straight out means.