Alternative Transportation modes – Urban Sprawl and the costs of various modes of transport, part 1

Living in America (or anywhere in the developed world) today, it is a given that you need transportation just to get around.  This is because the way we design our modern living environments have taken the car culture as the default status quo.  In cities with less zoning that puts people far way from shopping and other needed facilities, there are more options than in more spread out urbanization or rural areas.   In the next couple of blog posts we would like to overview the costs as well as the pros and cons of the many transport options available.

First, if you live in a city you need to be aware that cities use large inputs of resources and produce just as large outputs of wastes.  While cities and towns only occupy about 2% of land area they can use up to 75% of resources e.g. Chicago needs 58 times its living area for the inputs to keep the city running and that contribute to ‘sprawl.’  These inputs and outputs from sprawl include Transportation: Sprawl forces people to drive cars; Pollution: Increased driving causes increased air and water pollution; Health: Sprawl promotes physical inactivity because driving replaces walking during daily errands; Economics: Sprawl funnels tax dollars into required infrastructure (e.g., roads) for further new development and increased sprawl, and ; Land use: More land is developed and less is left as forests, fields, farmland, or ranchland. 

As we move into an uncertain energy future, we need to be aware of the energetics and economics of the various modes of transportation.  For this post, let’s look at the various energy needs and the cost for each person using the main transportation options.  We will then look at the many other options of transportation and how they stack up against mass transit.

If you want to get to work in the morning, and work over 10 miles away from home, there are 6 general ways of getting to work and back in a time effective manner (obviously commuter congestion increases the energy needed – not factored in at this time).  We can use Kilojoules as the measure of energy needed to move something – in this case the number of Kilojoules to move one person per mile with the various modes. 

  • You can drive yourself and you will use 2800 kJ per mile.  Obviously, this is an average based on a 200 lb person driving a mid-sized sedan doing 29 mpg.  The main advantage is individual convenience – you decide your schedule.   Add traffic congestion and this energy cost can easily double. 
  • If you car pool with 3 other people then the energy cost per person is about 1000 kJ – it is not just a quarter each of the single traveler since the extra weight from the other 3 people adds more fuel used, but it is greatly reduced from one person by themselves (4000 Kj total rather than 11,200 kJ).  The main disadvantage is that you have to coordinate the schedules of 4 people, and traffic congestion can easily double the energy needed.   
  • A van pool of 7 people is about 640 kJ per person per mile – the van is heavier and the extra weight of seven people needs to be taken into account.  Like a car pool, the scheduling of 7 people can be awkward but having a specific time-table of departure helps all the passengers reach a compromise.  Again, congestion will raise the energy needed.
  • Now a bus is even heavier, but can take between 40-80 people maximum.  If we assume a 60 passenger bus with average occupancy throughout its route, the energy cost is about 720 kJ per passenger mile.  The advantage of a bus is the greatly reduced numbers of cars on the road, thereby reducing congestion.  If the bus has a dedicated traffic lane thereby eliminating most of any congestion for itself, the minor disadvantage of a fixed travel schedule and the slightly higher kJ from a car pool, using the bus becomes a positive factor.
  • Riding the rail takes about 640 kJ per passenger mile, assuming about 90 passengers per commuter rail car.  A minor disadvantage is the fixed travel schedule, but congestion should be non-existent, and fuel use is electricity, which if from a renewable source makes it an ideal energetic mass transit option. 
  • Now some people actually use Airline travel as part of their jobs.  In a typical city to city flight, airline travel is not only the most energetic mode of travel but also the most polluting of any other option.  (a Boeing 737-800 carries 162 people while an Airbus 320 can carry 180 passengers).  The average energetics for airline travel are 6080 kJ per passenger mile.  If you read the previous posts about use of rail, it is useful to note that rail uses only 10% of the energy cpm of air travel. 

When you look at the cost per passenger mile for operating costs (Vehicle Operation (VO), Road/Rail Maintenance (RM), and Parking Costs (PC)) with the main forms of commuter travel then a similar picture is also seen.  Numbers are costs per passenger mile (cpm) broken up in to the various operating costs:

  • Bus – $1.05 cpm ($0.75 VO, $0.30 RM, $0 PC)
  • Commuter Rail – $0.48 cpm ($0.47 VO, $0.01 RM, $0 PC)
  • Light inner city Rail – $0.67 cpm ($0.66 VO, $0.01 RM, $0 PC)
  • Automobile large town – $0.81 cpm ($0.51 VO, $0.16 RM, $0.14 PC)
  • Automobile small city – $1.17 cpm ($0.61 VO, $0.17 RM, $0.39 PC)
  • Automobile large city – $1.67 cpm ($0.71 VO, $0.21 RM, $0.69 PC)  

The big differences seen in the automobile costs are the extra fuel used in congestion and wear and tear of operating the vehicle, the numbers of vehicles impacting the road surfaces (even more so in areas with heavy winter damage and high truck traffic), and of course parking fees.  Park in Denver versus Fort Collins and you will understand how expensive parking can be between the different urban centers.  A systems analysis of moving around shows that automobiles tend to be an expensive if not often unnecessary luxury to own.  In many cities such as New York, people forgo the automobile for mass transit and rent a car when they want to travel out of town.  In areas not served by good mass transit, there are still many options that can be used to get around cheaply, efficiently, and conveniently.  We’ll look at those in the next blog post.         

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