Yesterday I drove 6 hours, to Sacramento and back for a decade birthday of my brother-in-law and the way there was during rush hour out of the bay area. For what I am about to say, I do have a certain bias; few people would say that I drive slowly rather to the contrary.
One of those things that I can feel my blood pressure rise around are individuals who are not keeping up with the traffic flow. I have found that these people frequently drive a Prius. In conversations with Prius drivers they talk about working to get even higher mileage by limiting acceleration and therefore not necessarily keeping up with the car in front of them.
This is for all those Prius drivers; Have you thought about how self centered you are, how much more total gas you are causing everyone else to use?
Let’s take a commute along an expressway as the first example. Assume that the extra gap between the Prius and the car in front would at the normal density of cars on the road hold 3 additional cars. When a Prius goes through an intersection on a green light with traffic behind him, there will be 3 cars (or however many would fit in the excess gap) that don’t make it through the signal before it turns red. These 3 cars will then idle at the signal burning gas until it turns green, let’s say 30 seconds for the signal to keep the math easy or a total of 90 seconds extra idle time. This becomes true for most of the signals on a commute. If there are 10 signals the virtuous Prius driver has added 900 seconds of extra commute time to the collective everyone else who is driving. 900 Seconds is 15 minutes. How much gas is this? Except that it is worse than this. Those 3 cars that didn’t make it through the signal because some Prius had left a big gap, then mean that 3 less cars make it through the prior signal. At the 10th signal, there are 10 signals each with 3 cars that have had to wait. The total additional idling at signals for a 10 signal model with 30 seconds per signal cycle yields an added delay to the collective commute of 4950 seconds or 82 minutes. Mileage may vary depending on signals (count and duration) and Prius gaps.
Let’s take a freeway during rush hour. Let’s assume that the traffic packed, but moving at 30 miles per hour. Let’s assume that each normal car uses 53 feet of space for itself and the gap in front of it. This yields 100 cars per mile. The reality is that there is usually less space and higher density. If traffic is heavy like this for 5 miles. Our 3 car Prius gap is roughly 159 feet, or about 3.5 seconds of time. The Prius is delaying 5 miles, or 500 cars by that ~3.5 seconds which is roughly adding 30 minutes of driving time to the overall commute with each of the 500 cars behind the Prius suffering.
Do the desires of a few outweigh the needs of the many? Think about this the next time you see a car not keeping up with the car in front, and notice what type of car it may be. Are you one of those drivers?
Patrick Lynch
