Archive for April, 2015

What do Prius drivers and drunk drivers have in common?

OK.  Let me start by saying I fully support fuel-efficient driving and I do not condone driving under the influence.  Let me also confess that I drive a Prius.  After buying the car, I noticed that all of its indicators on energy efficiency were causing me to alter my driving habits.  See the photos below:

consumption prius toyota-prius-display

These displays are great, and they succeed in their objective of making additional data readily at hand for the driver.  They also encourage drivers to act in ways that are more fuel efficient, and this is a great thing.  Yet like all positive change, this one comes with a few drawbacks.  The first is that all of the display work tends to draw the driver’s eyes from the road to the display.  This was the initial change that led me to think about how Prius drivers’ driving habits may be quite different than those of many other vehicles.  Of course, I can think of plenty of other activities that alter driving habits (texting, selecting music on usb connections, etc), so let’s not dwell on this too much.  It was an anecdotal observation and nothing more.  And we can think of technological solutions to this problem, like projecting onto the windshield, as many luxury cars do already.

However as I drove more, I started to see other issues – both good and bad – with driving based on this new information.  I began to display tendencies toward hypermiling behavior.  Hypermiling is adjusting your driving habits to achieve greater fuel economy.  We all do this to an extent, yet I am struck by the driving habits of hard-core hypermilers and how much some of these habits/tendencies resemble those of driving under the influence.  To see a great list of ways to increase your fuel efficiency through hypermiling, see

As you can see from this list, there are a number of habits that could lead to “irrational” driving or displays of driving resembling that of driving under the influence. From that list, I’ll make just a few comparisons.  First, the hypermilers talk about “target driving” or driving at a constant (low) level of fuel consumption.  This leads to slowing down and speeding up as you go up and down hills.  Such variable speed driving is a common symptom of a driver not “paying attention”.  Second, hypermilers often try to drive the minimum speed limit, rather than the maximum (or more), something problematic on many of our highways.  Third, the hypermilers suggest coasting to slow down and minimizing the use of brakes.  They also suggest when braking is needed, you should brake hard and later than normal.  All of these habits can lead to improving fuel economy.  However, they (and many other techniques) also resemble the sporadic driving behaviors of impaired drivers.

A few caveats… First, I see a great need to learn how to drive more fuel efficiently, and many of these techniques work and can make tremendous differences in fuel consumption.  Second, the website I refer to above also emphasizes safety and following traffic regulations, noting the trade-offs of safety inherent in some of their suggestions.  Third, there is a middle road between unsafe driving and being more conscientious of our driving decisions.  I’ve learned a lot about my own driving through experimenting with these techniques.  They are quite different from the racing and muscle car mentality that I grew up with.  In a future post, I’d like to look into automotive engineering breakthroughs.  I think that the true engineering breakthroughs are now coming on the efficiency front rather than on the speed/acceleration front.  But I’ll leave that alone for the moment.

Any thoughts from police and whether they see this phenomena as well?