On the Questions of Dualmode Scale and Review Process

by Jim Haugen

It appears to me that one of the basic questions regarding the possibility of
an urban dualmode system (and one which I have never seen addressed), is:

What is a reasonable minimum starter size for a true dualmode system - one
which can be considered a success in having an important congestion impact,
attracting sufficient numbers of users/vehicle buyers?

The value of any network - internet, cellphones, transportation, etc. -
increases with the square of the size of the network. Let's apply this same
thinking to an initial dualmode urban installation.

Case 1 - Assume a 12 mile long two-way system with four access/egress points
and/or stations, an average of four miles apart. Further assume that the
average overall cost is $10 million per mile. And assume that such a
"network", with its very limited capability, attracts 1000 "bare bones"
vehicle buyers. The total system then costs $120 million; and vehicle
purchasers spend about $30 million (at an assumed cost of $30,000 per
vehicle). So such a very limited scale system implies total expenditures (or,
business opportunity) of about $150 million.

Case 2 - Assume a doubling of the network extent to 24 miles, with 8
"stations". This doubling in size implies that the number of vehicle
users/buyers quadruples to 4000. The system now costs $240 million and the
vehicles another $120 million, for a total expenditure of $360 million.

Case 3 - Double again to 48 miles and 16 stations. Quadrupling vehicle sales
then yields 16,000 buyers. Network cost becomes $480 million, and vehicle
costs are $$480 million, for a total expenditure of $960 million - almost $1

Case 4 - Double again to 96 miles and 32 stations. Quadrupling vehicle sales
now yields 64,000 vehicle buyers. Network cost becomes $960 million, vehicle
costs grow to $1,920 million, and total expenditures are almost $3 billion.

So what are the implications of considering the idea of different initial
scales of dualmode installation?


Last modified: July 27, 2001