Number Crunching in Transport

Wednesday, March 17, 2010

Transport Infrastructure Efficiency

Which kind of transport investments are the most efficient?

Sudhir Gota

This question bothers many policy makers. Answering this question is rather difficult as different projects require different scale of investments which carry variable load and satisfies diverse set of consumers. Also it would be wrong to assume that we can always build different alternatives physically having same bunch of people using it.

Knowing the above limitations, we can still assess efficiency of infrastructure requiring different set of investments – from High Cost such as Metro, to median ranged projects such as BRTS, Roads to low cost projects such as bikelanes and footpaths.

Let’s consider the following projects – Metro, BRTS, Expressway of 4 lane, two lane urban in high income zone, two lane urban in Low income zone, Bikeways and Footpaths and thus using the law of averages to evaluate the construction cost efficiency.

In order to compare efficiency – one needs average capacity and average cost. Let’s make an assumption as detailed in below table.

Capacity (average person/hour)

Cost (million USD)

1 km of Footpath of 2m wide

2400

0.1

1 km of Bikeways of 3m wide

3000

0.15

1km of two lane urban (Low income)

4500

1

1km of two lane urban (high income)

2600

1

1 km of Expressway of 4 lane

8500

3.5

1 km of BRTS

16000

2

1 km of Metro

60000

35

1. The Metro represented here is a replica of Bangalore Metro being constructed now. Its estimated to cost 35 million USD/Km.

2. BRTS – The BRTS taken above satisfies 8000 pphpd and costs 2 million USD/Km. this represents an average BRTS which is being constructed in many Asian cities.

3. Roads are tricky as they can carry a highly variable set of volume. So let’s assume LOS “B” and and 7% as peak hour volume. Lets also assume that a freight vehicle is equivalent to a vehicle carrying 15 passengers. ( this thumb rule matches with Value of time concept)

a. consider 35000 PCU/Day for Expressway – 4 lane

b. consider 15000 PCU/day for 2 lane urban road

c. Occupancy of 1,2,1.5 and 25 for two, three wheeler, car and Bus

d. Assume 50% mode share of freight in expressway and 9% in urban roads ( data Indian Roads)

e. Assume 55% two wheelers in low income and 55% Cars in high income areas

f. The other mode share epitomizes typical Asian roads ( 6% of vehicles as Bus)

4. Use Passenger Car Units to convert PCU’s into vehicles and then using occupancies break down the vehicles into passengers

5. Consider Bikelanes to carry 3000 cyclists/hour suggesting a dense network as seen in Delhi BRTS costing 0.15 million USD/km

6. Consider footpaths to carry 2400 persons/hour at a speed of 1.2 m/sec indicating LOS B. It may cost approx ) 1million USD/km.

Using the same money as required for constructing 1 km metro, one can on an average construct

  1. 18 km of BRTS
  2. 10 km of four lane Expressway
  3. 35 km of two lane urban road
  4. 235 km of Bikeways
  5. 350 km of footpaths

Thus normalizing different projects into same investment of say 1 km of metro and thus using the capacities and length, we can calculate efficiencies.

The below graph gives the efficiencies

The low cost projects such as bikeways and footpaths in fact provide best efficiency!!

They are 12 to 14 times more efficient than a system like metro. The above calculations can be made more useful by including operation costs and emissions. But the footpaths and bikelanes would be the winners but they often receive least attention and funding.

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