Red light means go (or does it?)

Should cyclists stop at red lights? Why do we feel such a strong urge to keep rolling? Should our behavior be guided by the law of the land or the laws of common courtesy? What would Isaac Newton and Thomas Aquinas have to say about the matter? Bringing their expertise to a discussion of the physics and philosophy of cyclists and red lights are Nigel Warburton of the Open University, the popular Philosophy Bites podcast and author of several classic textbooks on philosophy and Mark Miodownik, head of the Materials Research Group at King’s College London and writer and broadcaster.

Reading and riding: Christmas books special

Tim Dawson, cycling columnist for the Sunday Times, runs the Cycling Books website, the most compendious review website for cycling books. He joins me in the studio to discuss the literature of cycling, from Tour de France to cycle touring. Paul Fournel reads another extract from Need for the Bike. Below is a list of the books discussed in the show. If you would like to buy them, follow the links to Amazon and Resonance FM will get a share of anything you buy, even if it’s stuff not on the list. What a nice way to help your favourite bicycling art radio station!

The Classics
The Rider by Tim Krabbé
The Escape Artist by Matt Seaton
Need for the Bike by Paul Fournel

Tour de France
Bad to the Bone by James Waddington
Sweat of the Gods by Benjo Masso
Wide-eyed and Legless: Inside the Tour De France by Jeff Connor
Le Tour: A History of the Tour De France by Geoffrey Wheatcroft
My Comeback: Up Close and Personal by Lance Armstrong and Elizabeth Kreutz

Cycle touring & travel
Thunder and Sunshine by Alistair Humphreys
The Hungry Cyclist by Tom Kevilll-Davies
French Revolutions by Tim Moore
Full Tilt: Ireland To India With a Bicycle by Dervla Murphy
Transylvania and Beyond by Dervla Murphy
Blue River, Black Sea by Andrew Eames
A Bike Ride by Anne Mustoe

Advocacy, philosophy
Richard’s Bicycle Book by Richard Ballantine

Those we didn’t get time to talk about
Tomorrow We Ride by Jean Bobet
The Passion of Fausto Coppi by William Fotheringham
The Noiseless Tenor by James Starrs
Golden Age of Handbuilt Bikes and Competition Bikes by Jan Heine
Rouleur Annual 2009
Fixed: Global Fixed-Gear Bike Culture by Andrew Edwards and Max Leonard

To win copies of the current issues of Rouleur and The Ride Journal, send answers to the competition questions to bikeshow-at-resonancefm-dot-com. Thanks to these fine publications for donating the prizes.

And if that leaves you wanting more chat about cycling books, the 2007 Christmas books show is still online to listen again as is the show featuring Andrew and Philip Diprose of The Ride Journal. Matt Seaton wrote an excellent round-up over at The Guardian.

The physics of running red lights

It’s the Christmas silly season and newspapers are again rounding on cyclists (aka ‘lycra louts’) for running red lights and putting other road users at risk. Never mind the lack of any hard evidence of injuries or deaths caused by cyclists running red lights, it’s a story that appears to please news and online editors, such as at the Sunday Times yesterday and The Times today.

To borrow a memorable phrase from Peter Mandelson, I am intensely relaxed about cyclists running red lights, where it is safe to do so, i.e. when there is no obstruction caused to anyone using the junction who has priority at the time. Josh Hart has a great blog post on the subject.

Josh says it’s important not to confuse safe behaviour with law-abiding behaviour. “You can follow every law and still put yourself in a terribly dangerous position (i.e. in the door zone). By the same token, you can slow and look around carefully at red lights and stop signs and proceed when no one is coming and you’ll likely never get into trouble. Blindly following the law is a recipe for getting hurt on your bike. Better to trust your own hearing, sight, and instincts than the government’s rigid idea of ‘health and safety’.”

There’s some evidence to suggest that cyclists stopping at traffic lights on the left hand side make themselves more vulnerable to getting squashed by lorries and HGVs/LGVs that find it hard to see a cyclists in that position. This may explain why London Mayor Boris Johnson is considering allowing cyclists to turn left on red as well as riding the ‘wrong’ way down one-way streets as is already the practice in Brussels, among many other cities.

This would go some way towards addressing the second plank of Josh’s argument, that the Highway Code is inappropriate for cyclists. He say’s “unfortunately we live in a society where the needs of one class of road user are prioritised at the expense of more vulnerable road users.”

Buffalo Bill made the same point long ago on The Bike Show when he said that traffic rules were only needed to address the problem of automobiles on the roads, not cyclists, and therefore the rules should not apply to cyclists in the same way. As Josh argues, “The bicycle is a kind of a hybrid animal– somewhere between a pedestrian and a vehicle, and we need to treat it as such… Let’s stop trying to fit the round peg of cycling into the square hole of overly regimented traffic regulations.” Amen to that.

But before anyone accuses me of encouraging a free-for-all at red lights I strongly believe that to run a red light safely you need to have all your senses about you. You need to be looking hard enough to see that there’s no danger. You need to give way to pedestrians who have priority and anticipate those that have not yet stepped off the pavement. Setting traps to catch cyclists running red lights is so obviously an instance of wasting police time, though there is one small respect in which I do approve of Fixed Penalty Notices for red light jumping: If you don’t see the rozzer who nicks you, you weren’t looking hard enough to be safe running the red light, were you? So pay up and consider it a £30 lesson in cycle training. Sometimes when I’m cycling I can’t really be bothered with the effort involved in running red lights so I am quite happy to stop and wait, assuming there’s no potentially left-turning lorry looming over me.

What never seems to be discussed in the whole debate on red lights is why cyclists feel such a strong urge to run red lights, why it makes so much sense for us to do it. Those who write about it invariably ascribe it to the perceived arrogance and smugness of the cyclist, an expression of their innate sentiments of self-satisfaction and superiority. I feel a lot of things when riding the streets of London but superiority is rarely one of them. Certainly not when it’s pouring with rain and another bus has whistled past within a few inches of me, accompanied by a billowing cloud of filth and spray.

Cyclists run red lights not because we consider ourselves to be supreme beings but because of the forces of physics. The nature of the bicycle is that we have to use our own energy to move. Getting going is not simply a matter of disengaging the clutch with the left foot and easing the right foot onto the accelerator. When cyclists stop we have to give up all the kinetic energy we’ve built up and when we start again we have to overcome the inertia of our own body masss and that of the bicycle, the road resistance, wind, and so on. Cyclists running red lights are like people walking in a park who walk in the direction of where they want to go rather than following the paved paths. If enough of them are doing it, the result is a muddy rut in the grass. We don’t blame the walkers, we blame the planner who didn’t think about desire lines when making the paved paths.

It’s my sense that running red lights is much less about saving time than saving energy. A cyclist who runs red lights generally doesn’t save much time because she’ll usually end up stopping at a major junction at which point a law-abiding cyclist will have caught up, or nearly caught up. The vital point is that the red light running cyclist will have expended much less energy. And this is important. Cycling can be hard work, and the perception of effort puts a lot of people off riding bikes. The easier it is, the more people are likely to take it up. (By the same token, all those roadies who use their daily commutes to work out as a form of training, should perhaps reconsider their red light running, since stopping means they use more energy and therefore get a better workout. The expenditure of energy to get up to cruising speed might be considered as a form of interval training.)

All this is just my intuition based on my own experiences of cycling. I’d really like to find a physicist or an engineer who would be able to properly quantify the time loss and the energy loss involved in stopping at red lights. I think the results would be interesting and would help illiuminate the debate. The implications might go beyond the debate on red light running and could be useful for transport planners who, if you ask me, should be working hard to design routes for cyclists that minimise the amount of stopping that’s required. If you’re a physicist or an engineer who could apply your knowledge to these questions, please get in touch.