Comments on: More Thoughts on Driving

By: Mike

Mike — Wed, 25 Jul 2007 06:27:15 +0000

How did the gas savings of your driving play out? Have you found yourself spending substantially less on gas than you otherwise would?

As far as the traffic circle/roundabout/rotary question, IS there a reason that they’re not prevalent in the US (there are a few in Boston and most visitors from other states hate them)? Safety?

By: Matt

Matt — Mon, 23 Jul 2007 06:00:06 +0000

Being a pious driver of a car that has the kind of feedback that you mentioned, there are a couple of additional perks that people tend to leave out. First, I find that I actually drive a lot less than I did with my old car, simply because I don’t want to lower my average tank MPG. The best way to keep that number up there (in my case, about 47-52) is to employ the techniques you mentioned above (plus the “pulse and glide” method used by lots of hybrid drivers) on trips that last longer than 15 or 20 minutes, and have stretches of flat or downhill road. Getting in the car for the 5 minute drive to the store is the single easiest way to lower the tank average. This is because a) it takes the ICE (internal combustion engine) about 5-7 minutes to fully warm up, during which time it is the least efficient, both in terms of mileage and emissions, and b) there’s no combination of road grade (flat both ways, downhill one way) that will give the round trip a chance to click the average MPG up a few points.

The second thing is that hybrids have a unique feel to them in terms of the ICE. When I’m driving less than about 42 MPH, I can usually feel whether the ICE is turned on, and can adjust several things to turn it off and be powered solely by the electric motor. This is something that took a lot of practice, since the ICE is much quieter (and less powerful) than the engine in most cars, but now that I’ve got it figured out, I’m hyper-aware of when I’m actually consuming gas. Of course, this is a feature that’s unique to gas-electric hybrids, and even when running on the motor, there is still an inherent use of gasoline. Still, if you plan your trips just right (taking routes with the fewest uphill stretches and driving with the techniques you mentioned), the amount of gas consumed by the ICE can be minimized.

All of that is aside from the fact that I’m consciously trying to use less gas (I’m a pious liberal, remember?). In general, if my destination is reasonably within walking or biking distance, my (possibly neurotic) desire to have the highest MPG on a tank pretty much keeps me from driving, no matter how lazy I might feel. This used to be true when I didn’t own a hybrid, but I firmly believe that having that little 3-digit number staring me in the face when I get in the car actually makes me consume less.

By: Alex

Alex — Mon, 23 Jul 2007 02:34:35 +0000

Leo is right on, roundabouts are much more efficient than stop signs.

Last quarter I conducted some research on driver knowledge of vehicular energy consumption. We asked whether people knew about behavioral options to improve fuel efficiency and if they implemented them. Even though the majority of our sample drove alternative-fueled vehicles and were aware of measures to reduce fuel consumption (the most substantial obviously is speed) they rarely enacted them because they were ‘in a hurry’–the pitiful race you speak of.

It’s not clear if purely transportation-related policies can change behavior in the desired direction since there seem to be deeper sociocultural forces at work. Somehow getting to the root of the problem would be ideal…

By: Leo

Leo — Wed, 18 Jul 2007 16:31:16 +0000

I believe most Europeans are surprised by the ubiquity of stop signs here in the US. In many small European towns you’ll be hard pressed to find one stop sign — people simply follow one rule: yield to the right (in addition to ‘have some common sense and be aware of your surroundings’).

Traffic circles are also a good way of letting traffic self-organize (the rule here is to always yield to those already in the circle), and they deal pretty well with varying levels of traffic!

By: Brynn Evans

Brynn Evans — Wed, 18 Jul 2007 04:53:44 +0000

It’s good to be aware of your driving behavior and mentality, but now think about it from a biker’s perspective! I just love speeding past a line of stopped cars, especially when those cars had been passing me a little ways back. In fact, on my way to work on Monday I biked right by another intern (who was driving) — we were 2 miles from work. To my surprise, I pulled into the parking lot right as he was getting out of his car! Hahahahahaha.