On its face, this is a true statement: A car going 55 mph will generally have better fuel economy than the same vehicle going 70 or 75 miles per hour. For an individual on an individual trip this might result in a 10 to 20 percent savings in fuel consumption.There is nothing in current law that prevents individuals from driving at slower speeds to achieve these savings, as long as they stay in the right hand lane and let faster traffic pass on the left.
However, when it comes to the impact of driving slower on high speed highways, primarily Interstate highways, the savings are inconsequential.
First, of the 3.8 million miles of streets, roads, and highways only 46,000 miles are interstates. Of those there are significant portions already posted at 55 mph, or even lower. There are also periods of time when congestion reduces actual speeds to well below even 55 mph.
Then there are construction zones and weather induced speed reductions. In the end, even including all highways posted with higher than 55 mph speed limits I would estimate less than two percent of all our streets roads and highways currently boast speed limits in excess of 55 miles per hour.
True, these highways may carry a quarter of all traffic, but when considering all the instances when this traffic is constrained to lower speeds, applying a mandatory federal limit of 55 Mph will have insignificant influence on national fuel consumption. (This conclusion is reinforced by the National Academy of Sciences Transportation Research Board which estimated that in 1984 raising the 55 mph federal limit to 65 mph would increase national fuel consumption by less than two tenths of one percent.)
"Speeders" burn more than their share of fuel
First, let's put to rest that drivers traveling at speeds of 70 to 80 mph on good highways are "speeders" in the pejorative sense. They are doing nothing that is unacceptably dangerous or anti-social. Further, is it rational to label the driver of a small sedan who averages 30 mpg at 75 mph (instead of 35 mpg at 55 mph) as "wasteful" while lauding the driver of a large SUV or RV who is achieving 14 mpg at 55 mph (instead of 11 mpg at 75)?
I'm not throwing stones at any group of vehicle owners, but it is equally inappropriate to assign derogatory labels to drivers based on how fast they choose to drive (within reason).
In the rush to condemn it is forgotten that those who consume more fuel also contribute more to the maintenance, upkeep, and improvement of the highway system. They are not "getting a free ride" and second guessing another driver's trade-offs between time, speed, and costs is a useless exercise.
The government needs to do something
Yes and no. The government needs to address those regulations, practices, and policies that waste fuel resources. The political philosophy needs to switch to accommodating motorists, expediting traffic flow, maximizing travel choices, and applying user fees to get the most benefit for the dollar spent. Practical actions like synchronizing traffic lights in urban areas, removing unnecessary stop signs, and RAISING speed limits on main thoroughfares in urban and suburban areas could save many millions of barrels of oil on an ongoing basis.
The federal and many state governments need to do 180 degree turn on their promotion of toll roads. Tolls drive traffic to secondary roads less able to handle large trucks and heavy traffic. Local and state officials respond by plugging up and constricting traffic flow on secondary roads to drive traffic to the toll roads.
Needed improvements on secondary roads are deliberately postponed or ignored, again to drive traffic to the toll roads. Eliminate the tolls and traffic will naturally gravitate to the main corridors, while the secondary roads can be maintained and managed to efficiently carry local traffic. Again, one of the prime benefits will be substantial fuel savings.
What we don't need the government to do is establish low arbitrary speed limits, (that won't be complied with) rationing schemes, more ethanol fiascos, or new taxes on oil companies that will obviously be passed right back to the consumer.
Ultimately, we'll get a handle on this situation by transitioning to more efficient vehicles that operate on a variety of fuels, as well as changes in travel patterns, work and home relationships, and implementing technologies that we haven't even imagined. Our greatest challenge may well be keeping the government from "solving the problem."