Piloting a car takes 70 calories per hour, 10 calories more than being a passenger. It costs $8,500 to own and operate a car for a year, or 35 cents a passenger mile. The average speed of a car trip is 33 mph. In the average commute time of 20 minutes, you can cover 11 miles in a car. Only 20% of car miles traveled are for work, another 20% is for recreation and musing, and the rest is for other errands.
Your chances of dying in traffic are 0.8 per 100 million miles traveled, based on 42 thousand fatalities in 5 trillion passenger miles. At the average speed of 33 mph, your chances of dying in traffic are 27 in 100 million hours.
A standard traffic lane is 12 feet wide, though a car is only 6 feet wide and a truck or bus is 8 feet wide. The extra space is to allow for comfort of steering. As vehicles need 2 seconds of clear space between them, a car at 33 MPH needs 100 feet between vehicles. So the average car needs 3% of an acre of road for itself, lane comfort, and stopping distance. The most important part of any journey in traffic is parking in a 9’ x 18’ paved space at either end. After all, you cannot enjoy a place unless you can get out of your car, and you can’t just leave it sitting in the way of other cars. Each car needs at least 1% of an acre for parking, bringing its total space needs to 4%. Overall, an area about the size of West Virginia is paved for roads and parking to accommodate traffic, an average of 6.5% of an acre for each of 240 million cars, trucks and SUVs. Per car occupant, this works out to =6.5/1.6
The nationwide average occupancy of a vehicle in traffic is 1.6 people per car. The maximum capacity of a lane of traffic is 2,000 vph, or 3,200 pph. As traffic approaches this capacity, the quality and safety of the route declines dramatically, causing drivers to slow down and reduce the capacity of the route. The design capacity of most lanes is closer to 500 vph as a result. The energy consumption by cars is 3,360 BTU per passenger mile, based on 3 trillion VMT.
The cost of building roads is between 500k and 6 million per lane mile, depending on the function and setting of the roadway. Roadways can be built piecemeal, paving an intersection or block at a time as traffic demands. This is how we’ve built 8.5 million lane miles in the last century. The public cost of maintenance for roads is $9,000 per lane mile for government agencies, but $230,000 per lane mile for drivers on the roads, for a maintenance bill of 76 billion dollars in 2002, and an operations bill of 1.9 trillion dollars, paid by all of us. 1.9 trillion is about 13% of our GDP, by the way. Federal subsidies are mostly in the form of a trust fund, fed by the gas tax. This user fee collects the most from those that use the roads most: long distance drivers in heavy vehicles. Gas Tax revenues to the highway trust fund only covers about 30% of the 112 billion we spend on road construction and maintenance every year.