Archive for September, 2009

Transportation is Broken – a New Solution is Needed

Tuesday, September 15th, 2009

Transportation is Broken – a New Solution is Needed

A review of the major characteristics of our urban transportation system quickly reveals that it is thoroughly broken. Of even greater concern is the fact that most of the solutions currently gaining traction will do little to solve the most pressing problems.

The problem

Let’s start by comparing how various indicators have grown relative to population growth over the past 20 years. Table 1 lists major transportation characteristics and their growth over a 20 year period. The horizontal red line shows the U.S. population growth over that time (about 24%), and the discussion below compares the growth of each characteristic to the population growth, in order to put things in perspective (if nothing changed, these characteristics could all be expected to grow at the same rate as the population has grown).


Accidents. The total number of accidents has actually declined. While this is the only factor to decline, and clearly a good thing, it is still not nearly enough. Over 40,000 people are still killed on US roads annually (compared with total U.S. deaths in Vietnam – 58,159; Iraq – 4,334; 9/11 – 2,993), and road traffic injuries are one of the top three causes of death for people aged between 5 and 44 years worldwide. Lest you think the US is much safer than the rest of the world, we are not. There are approximately 60 countries with lower death rates per 100,000 population. Improving safety is no easy feat, since advances in safety technology can be easily offset by societal changes, such as texting while driving.

Use of Public Transportation. Transit use grew a little more than population but much less than passenger vehicle miles traveled. Try as we might, we just cannot convince people to leave their cars for transit. During the recent period of high gasoline prices, a small jump in transit use was experienced. This caused problems for transit agencies around the country, because they lose money on each rider! This unsustainable practice was exacerbated by reduced tax-based subsidies and meant that many agencies had to reduce service at the precise time they should have been increasing it. Subsidized transit systems may be necessary to ensure that the disadvantaged have reasonably priced transportation. However, a sustainable transit system, that can rise to meet changing demand, needs to cover at least its operating expenses from the fare box – something that few US transit systems can accomplish.

Transportation Energy Use. This is growing an alarming 50% faster than the population and a large portion of this energy comes from foreign oil suppliers. 96.6% of all transportation energy use is petroleum-based and any growth at all is problematic. As cheap oil resources are depleted, and as countries such as India and China dramatically increase their oil use, cost of oil is likely to rise steeply and cause serious problems for transportation.

Delays Caused by Congestion. As more and more cities face rush-hour gridlock (and rush-hours get longer and longer), this factor is growing twice as fast as the population and congestion now wastes 3.5 billion man-hours every year. We do not seem to be able to build ourselves out of this problem. Consider I-25 through Denver; Two years after a major improvement project took it from six to eight lanes plus light rail, it regularly suffers congestion similar to what it did before the construction. Paradoxically, even in bad traffic, the light rail train seldom passes the automobiles. This is because the light rail system only averages under 25 mph. By the way, the light rail’s two lines cost about the same to build as the eight lanes of highway, even though they carry much less traffic.

Passenger Vehicle Miles Travelled. The amount of driving we do is outgrowing the population by almost three times! This high level of passenger vehicle use is widely seen as being unsustainable. The energy used (and the related foreign oil dependence) is seen by many as being the major issue. However, automobile use brings numerous other problems. While accidents and congestion are discussed separately, two other problems are real estate/infrastructure and automobile manufacture. Each car typically requires four parking spaces (one at home, one at work and two others for intermittent use). The cost of this infrastructure (these spaces are typically paved and often roofed) and the street/road/highway infrastructure, needed to support our automobile use, is enormous. At the same time, the real estate used to support automobiles increases the cost of other utilities and decreases the quality of urban living. Furthermore, the cost of highways is increasing as design standards are continually raised in an attempt to reduce accidents. In addition, the tax revenue to support this infrastructure has not kept pace with the need, and we are likely to face increased taxes and/or more and more tolled highways. The cost to society of individual automobile ownership is rising as we strive to make cars more sustainable. It’s time we took a long hard look at what automobile ownership really costs.

Logistics Costs. These are the costs of moving goods and they have increased far faster than the population has grown. At this pace, logistics costs are set to have major impacts on our economy. Part of the reason is that we move a very large proportion of goods by semi trucks rather than rail. Rail is a far more efficient way to move goods, but we lack the infrastructure to economically collect and distribute goods at the ends of the rail lines. Shipping suffered from a similar problem, wherein the cost of handling goods in harbors exceeded the cost of shipping them over the seas. This changed with the advent of container ships. A similar revolution is needed for rail.

Greenhouse Gas Emissions. Transportation accounted for 47% of the net increase in total U.S. greenhouse gas emissions since 1990. It currently contributes 34% of all greenhouse gas emissions. Reducing transportation-related greenhouse gases requires reducing the amount of energy used by transportation, as well as changing the primary source of that energy.

A solution

Think transit is the solution? Think again. In the U.S., transit uses (wastes) as much energy per passenger mile as the automobile. This is largely because trains and buses run around empty most of the day. Transit infrastructure is expensive to build, consumes much real estate and resources, and its construction contributes significantly to greenhouse gases. High speed rail and air travel may be good solutions for long distances, but both suffer a last mile (or last many mile) problem and do nothing for urban mobility.

It is amazing to think that we are still using the stagecoach model for transit. A stagecoach runs on fixed routes with designated stops. There is seldom a stop at the desired origin and destination (the first/last mile problem mentioned above). The vehicle accommodates many people, to spread the cost of the driver, and has to stop whenever somebody needs to get on or off. All we have done to this model is make the vehicles bigger, turn the stops into stations and the routes into corridors. The ride may be a little smoother and the speed a little higher, but the quality of service has hardly improved. A rail system, with top speeds in the fifties and stations every mile, has an average speed under 25mph. “Modern” street cars often have average speeds in the single digits. It is no wonder transit only achieves a mode share of around 4%. The model is broken and we need to quit trying to fix it. We need a new model.

What if you did not have to wait for transit, you always got a seat, and it took you where you want to go without stopping? Would you use it? The only mode of transportation that currently operates this way is the automobile at 3a.m. Even then, stops at “dumb” traffic signals for no crossing traffic at all are often required. Amazingly enough, transit that operates this way was invented over fifty years ago. It is called personal rapid transit (PRT) and it can be likened to automated (driverless) taxis operating on a system of guideways. The reasons PRT could help solve our transportation problems are:

1. It has a high level of service (more like a car than a bus) and really can attract drivers from their cars.

  1. It uses about a third the energy of most other modes.
  2. It is electrically powered so, as we convert the grid to renewable sources of energy, we automatically also convert PRT-based transportation.
  3. It has proven to be about a hundred times safer than conventional transit.
  4. Elevated or buried (PRT tunnels are much smaller to move the same number of people) guideways do not use up real estate or cause neighborhood severance.
  5. Small vehicle sizes (like a small automobile) require minimal infrastructure.
  6. Each automated T-Pod (transportation pod) will be reused fifty or more times a day – an efficient use of manufacturing resources and a reduced need for parking.
  7. In off-peak times, unused T-Pods wait in stations or depots – there is much reduced empty vehicle movement.

Table 2 below shows my opinion of the extent to which various solutions are likely to have a positive impact on the transportation problems mentioned at the beginning of this discussion. 0 = no impact, 1 = some impact, 2 = significant impact. Certainly, some will argue with my ratings, which are based on my own opinions and analyses. In addition, PRT has yet to be proven in large applications. The point is that PRT appears to have the potential for quite significant impacts across the board, yet it is receiving attention that is dramatically disproportionate to this potential.



US DOT Bureau of Transportation Statistics

World Health Organization

US DOT Bureau of Transportation Statistics

US Department of Energy

American Council for an Energy-Efficient Economy

Steiner, C., $20 Per Gallon

2009 Urban Mobility Report

Federal Highway Administration

Federal Highway Administration

U.S. Environmental Protection Agency

U.S. Department of Transportation

Muller, P.J., Personal Rapid Transit Safety and Security on a University Campus