Advance Cycle Boxes

[jack]

Just before traffic lights, there is a cycle-lane like box the width of the main lane, in which cyclists can stop at lights without being rear-ended by cars.

0. Is there an official name for them? "Advance cycle box" is in my head, is is equally likely to be something else entirely, or made up.

1. What is the intended use if the cyclist approaches the traffic lights behind three cars? I feel it should be obvious what they're supposed to do, but admit I can't tell. Obviously if you can accelerate briskly to 20mph, there's no problem, but if you can't, or don't want to?

Undertake if there is a clear cycle lane, else wait in the queue? Always undertake if you can? (But it's not clear when the highway code permits undertaking.) Overtake if you can? (But this is unlikely to be possible.) Always wait? (But that leaves a frustrated driver behind you.) Dismount and cross the intersection from the pavement? (But that's annoying and takes several times as long.)

2. If it were safe to do either, which would delay the drivers least: moving ahead to the cycle box, or waiting in turn. One way, the drivers ahead go past, but the one behind probably misses the lights. The other, all the drivers are delayed until the road is wide enough to overtake safely again.

3. What do you do?

I feel silly for not knowing, but most of the time, it doesn't come up, either because there's not enough of a queue, or the road is wide enough to permit cars overtaking cycles safely. And then when it does, I don't actually know.

Comments

[cartesiandaemon.livejournal.com]

(This DFT leaflet from between 1993 and 1995 provides some interesting early perspective on the design of ASLs.)

Thanks, that's really interesting.

It's sweet of you to worry about this.

:) Thank you. At a minimum I don't want to inconvenience people without any cause, and I'd rather not inconvenience people at all if it's little trouble to me.

I suggest you try it both ways and see what the outcomes are.

I've certainly experienced both. I'm thinking mainly of the crossing Milton Road into Greenend Road from King's Hedge's Road, as I often do coming home from work, when the left-turn lane is busy.

Probably, if the queue is car, car, car, cycle, car, then the fourth car just misses the lights whatever the cyclist does, and the cyclist can either overtake, and delay the first three cars by the length of time it takes to cross the junction, or stay behind, and miss the lights.

(Although, come to think of it, the delay may be less than that, if a cyclist can accelerate faster to start with, and can start from the advance box without having to wait behind the cars. Maybe that would let the fourth car pass the lights?)

[gareth-rees.livejournal.com]

I use that junction a lot (mostly turning right from Kings Hedges Road into Milton Road, but all the other movements from time to time). In your case (going straight across from KHR to GER) if you're really concerned about not holding anyone up you could move slightly to the left once you're out of the path of left-turning traffic and allow motor traffic to overtake you in the junction -- I think the junction is wide enough to do this reasonably safely.

[cartesiandaemon.livejournal.com]

Yeah, I sometimes do do that when I'm at the front anyway. It's definitely an option. If there's just one or two cars, they can generally pass (or turn right) in the width of the junction. But it feels a bit dodgy, like it's not good practice because if there's more than two cars, then you have to squeeze through the traffic lights on the other side, really close to a car coming from behind. (Or be stranded in the junction when the Milton Road southbound traffic starts, or pull out in front of the car[1] before anyone had a chance to overtake)

[1] I feel no-one considers, when wondering whether to make room for someone to pull out in front of them, if they only pulled in to the left in the first place to let people pass. Which is understandable, but means pulling in to the left means you then get stuck waiting for a gap :)

[pizza.maircrosoft.com (from livejournal.com)]

ah. take two little clicker things that timestamp clicks (do such things exist?), and stand by the lights - hm, three little clicker things - and click one of them when the lights change, one of them when a car goes through the lights, and one of them when a bicycle does. Spend about six hours collecting data, each day for a week, then feed it all to a computer and generate a model of accelerations and thingies.

three clickers would be inconvenient as most people only have two hands. perhaps there is a better way. maybe a laptop (with lots of battery) and a little recording program and three designated keys.

[cartesiandaemon.livejournal.com]

LOL. I seriously considered doing that for a few hours, and just getting some informal estimates of how many cars normally go through the lights, and what normally happens if there's a bike.

[pizza.maircrosoft.com (from livejournal.com)]

fun for all the family. do it with livredor when she is visiting.