Friday, July 29, 2005

Middle Ground

There have been a couple of columnists in the Pioneer-Press, Saint Paul's newspaper, ripping cyclists for one thing or another. The guys who wrote these are just columnists so their pieces are long on blustery opinion and short on objective facts of the type an actual reporter might get together. However, they did get me to thinking.

A common thread in both was cyclist's failure to stop at Stop signs. Now, leaving aside for the moment the point that most motorists don't stop at Stop signs either, I was looking around on the web to see what information there was about bicycles and Stop signs. Interestingly, a physics professor at Berkeley has done some work on Physics and Bicycles and points out that there is a good reason cyclists don't like to stop; conservation of energy. (you can read the version for civilians and columnists here and see all the math here). The main point of this is that 1) it takes much less energy to keep a bicycle (or car, for that matter) moving than it does to get it moving in the first place and 2) in a roadway with a Stop sign every hundred meters or so, bringing a bike to a full stop and then restarting it means that a cyclist has to expend roughly 500W (Watts) of power to maintain a 12.5 mph pace versus roughly 100W to maintain a 12.5 mph pace without stopping at all. What makes this interesting is that 100-150W is within the sustainable power range of most people whereas 500W is highly-conditioned bike-racer type output. No wonder we don't like to stop.

If you are like me, or like the majority of automobiles, you neither come to a full, complete stop at each stop sign nor do you breeze blithely on through with insouciant unconcern. Instead, you slow down, look both ways, and, if it's clear, carry on. What may be maddening to motorists is that bikes don't slow down as much as cars. I think this is because cyclists generally have much better situational awareness on a bike than motorists do in a car (I speak as someone who both rides and drives). My Atlantis is unusually tall, but even on my Marin my eye level is slightly higher than that of a driver of a Suburban or Ford F-150 and way above that of drivers of minivans or sedans. I like this visibility, and it is one reason I'd be terrified of a recumbent in the city--you couldn't see anything and nobody could see you.

In addition to the better visibility, cyclists can hear better on bikes than can people in enclosed cars with engine noise, fans, the radio, etc. As a result, I’m speculating that the speed to which bikes slow down before proceeding at stop signs is faster than the speed to which cars slow down. The result is annoyance, the same annoyance I've felt when driving 72 in a 55-mph zone and someone overtakes me doing 76; "Hey! That's unsafe, you scofflaw bastard!", ignoring my own transgression. Rather than seethe privately about it, the Pioneer-Press columnists wrote about it in their paper.

So, motorists get annoyed at cyclists for slowing down to only 8 mph at Stop signs when they, responsible law-abiding citizens that they are, slow all the way down to 3 mph. Well, guess what, neither one is a full stop, both are breaking the law, so I could do with a little less righteous indignation from the motorist crowd on this point. As for those cyclists who do go sailing blithely on through Stop signs and red lights, they’ll soon be thinned from the herd and I will feel the same lack of sympathy for them that I do when adult snowmobilers fall through the ice on lakes and die. Stupidity has a way of catching up with people.

While I was looking up this stuff I thought also about the columnist comments about how bikes are hogging the roads. I looked out at our parking lot at work, the east side of which is currently being resurfaced. We must have ten acres of parking. The parking footprint is way bigger than the building footprint. In fact, as I look around, the company maintains a bigger space for my car than it does for me. Hey! There is a bike rack on one side on one of the little decorative gravel islands, then this enormous semi-circle with parking for hundreds of cars being maintained at great cost. I wondered, how much room does a car take up in the road compared to a bike? The Pioneer-Press columns were certainly fact-free zones and no help. Let’s look up some numbers.

Well, my Atlantis, from the front of the front tire to the back of the rear fender, is 72 inches long. The handlebar, with my hands on the brake levers, is about 22 inches wide. Thus, a rectangle to contain the bike would have to be 1,584 square inches, or 11 square feet. Remember, this is a long-wheelbase touring frame in the biggest size available (68cm) and unusually wide handlebars (48cm). Our main car, a 2004 Toyota Avalon, is 191.9 inches long and 71.7 inches wide, requiring an area of 95.6 square feet. (These auto figures, by the way, all come from the Automobile Invoice Service New Car Cost Guide, which is the sort of thing we have lying around at work). Move up to a Chevrolet Suburban, at 219.3 inches long and 78.9 inches wide, and you're looking at 120.2 square feet. But the Avalon will carry five people and the Suburban seven, you say. Sure they will, but most of them don't most of the time. In my daily commute to work, nearly all the vehicles I see are driver-only, as I am when I drive.

Given this, it can be a bit grating when someone driving a vehicle with a 95-square-foot footprint is complaining about someone riding a vehicle with a 11-square-foot footprint "hogging the road". (I used Visio to do a precise diagram of three vehicles' Comparative Footprints so you can decide for yourself who hogs the road.)

The power output was interesting as well. The study I cited says that regular non-athletic cyclists (like me) should be able to maintain 100 watts of output without undue effort. I don't know what my maximum output would be, but I'm going to say maybe 200 watts. How much power does a car use to move? Well, the Avalon has a 210-hp engine (the new 2005s are 280), which is 156,660 watts of power; the Suburban has a 295-hp engine, or 220,000 watts of power. They need all that power to move all that weight, 3,400 lbs curb weight for the Avalon and 5,470 for the Suburban versus 30 pounds for my Atlantis. Think about that next time you see someone stop in the fire lane at Blockbuster in their 3,000-6,000-lb, 100,000-235,000 watt vehicle to drop off a 4-ounce DVD. That's when riding a 30-lb machine at a decent cruising speed (12.5 mph) over short to intermediate distances with typical small payloads occupying less road and parking space, all for less power output than just the headlights on a car, makes sense.

As an aside, a vehicle that is often savaged for its excesses is the Hummer H2. This is a vehicle favored by military wannabes although of course it's just a boxy body, one reminiscent of the actual military Humvee (or Honda Element, for that matter), on a Chevy Tahoe frame. One of these days I am going to dress nicely and drive the Avalon to the local Cadillac/Hummer dealership and test drive one of these puppies. In the meantime, it's interesting to note that the H2 is actually 2 inches shorter (in length, not height) than our Avalon, although it is nearly 10 inches wider without the mirrors. In overall footprint, the H2 is actually a hair smaller than the popular Honda Odyssey minivan. The weird thing is the weight; the Odyssey comes in at 4,500 pounds, the H2 at 6,400 pounds empty. Jesus, what’s this thing made of, spent uranium? No wonder it needs 316 horsepower (236,000 watts) to get moving.

Anyway, I found it interesting to look up some actual facts regarding autos and bikes. Too much of the discussion, whether in these Pioneer-Press opinion columns or on many bike blogs, is pointless name-calling, people yelling past each other with hardly any exchange of actual data. Various parties may enjoy dismissing motorists as clueless criminal foul-smelling oil sluts and cyclists as Spandex-clad scofflaw Lance wannabe bike faggots, but I ride and I drive, I don't think I'm clueless, I'm neither a Lance nor a military wannabe and I think there is some middle ground in the transportation mix that makes more sense than where we are now, that costs less, uses less energy, pollutes less yet meets our transportation needs. I'm working to find that middle ground for myself. I'd encourage you to do the same.

5 comments:

Katie said...

Hi Matt,

We did 13.37 miles on Sunday morning riding to church. Jim 's folk had the kids so we were all alone. We had a good trip. By the end of Mass I had cooled down. On our way back from church we stopped and had breakfast. I was happily tired the rest of the day.
Katie

Jim said...

Katie: I was confused at first. The word "mass" has a different connotation related to bicycling and it took me a minute to undertstand what you were talking about. Anyway, congratulations on the ride to church.

Matt:
This is a very interesting post. As much as I like pointless name-calling, I like your objective reasoning even more. I'll link to this post.

Anonymous said...

Sometimes my cyclist guilt gets to me when I don't stop for every stop sign. But honestly, by the time I get to the stop sign I have a really good idea if I need to stop or not. As you correctly point out, I'm moving more slowly, I can hear much better and I can really see what is going on around me. So I feel justified in just slowing down enough so a quick stop won't throw me over my handle bars.

I've been reading a lot about biking this summer and one thing I have discovered is that it was cyclists who first called for paving roads. They found paved roads much easier to ride than rutted dirt road. I think about this a lot when I hear about bicyclists "hogging" the road.

Great post.

Anonymous said...

It's also, of course, much easier to stop quickly on a bicycle. I agree with the previous poster that a cyclist has a very good idea of whether or not she'll need to stop by the time she's near the stop sign. But if she's mistaken, and a car is coming through the intersection, it will be easy for her to make a quick stop (and not even dangerous, unless she was trying to race through the stop sign at cruising speed, which is silly and unsafe).

I do always, always stop and wait for red lights, though. My sense is that cars travel faster on most roads with traffic signals (as opposed to stop signs), so I'm more likely not to realize in time that a car is coming through an intersection with a signal.

Jeromy said...

Having been car-free for seven years now in Texas, where large vehicles are more valued than large hats, I feel I have a pretty keen sense for what is happening around me on my bike and for how to ride safely. I agree that it is much easier to assess one's surroundings from a bike than from a car, and given its lightness, the bicycle is much more agile and easier to stop. This being said, I do not nor have I ever condoned cycling as though cyclists have some special right to the road that cars do not (not that you or another poster have stated this, but many cyclists do operate this way). I always practice vehicular riding - Texas law treats bicycles as vehicles with all the rights and responsibilites of motorized vehicles. This makes me much safer on the roads as I am more predictable from the motorists viewpoint. Of course, however, as any motorist, I rarely if ever come to a complete stop at a sign (but always do at a red light) when I see that the path is crystal clear. It seems though that while vehicular riding makes me safer in one sense, I will never in my lifetime escape the thick headed abuse from drivers like Big Gulps hurled out windows or (seemingly) conscious merging into me as if I were not there. Anyway, the debate on how to best get along between drivers and cyclists still has a way to go.