Any proposed public transit infrastructure should be thoroughly vetted to assess the degree to which it will meet the transit needs of the intended market. This is especially true when relevant costs reach the absurd levels of today's highly over priced market for public works.

Boston's proposed Green Line 'light' rail extension is estimated to cost over $1 billion for 4.24 miles of new service. This transit mode was initially dubbed 'light' on account of its lower infrastructure needs, lower speeds, lower capacities, and lower associated costs relative to that of 'heavy' rail transit. It is now clear that 'light' no longer applies to this last element.

5 - The Name Game

In the U.S., light rail has been selected by many cities to serve transit needs, but for the wrong reason, and under false pretenses.  The heralded 'lower' costs of light rail, compared to heavy rail, was used to get it on the public agenda.  Cities with no experience in mass transit merely saw a vehicle on a rail.

Ironically, the characteristic of light rail which most lowered its cost (compared to heavy rail), has largely been eliminated in almost all modern day implementations in the U.S.   Thus, cities get a light rail system at a heavy rail cost.   The public is led to believe they can pay for a light rail system, but have it customized to resemble heavy rail at no extra expense.  This is all done by slight of labels, calling it 'light rail' for public consumption while paying a heavy rail bill.   And, since no one is actually responsible for the results, we frequently get a hybrid that is a poor solution for the market to be served, and therefore a poor value.

Capital Cost (Millions)
Cost per Mile
Cost Increase Notes



Cost per mile up 54    percent from 1999.

Kansas City-Southtown
2000 data not available
Cost per mile up 30 percent from 1999
New Jersey: Hudson-Bergen II


Orange County
Cost per mile up 10 percent from 1999
2000 data not available
Phoenix (2000)
Cost per mile up 59 percent from 1999

Portland-North South
2000 data not available
Salt Lake City
Different route from 1999.
San Diego-Mid Coast
Cost per mile up 18 percent from 1999
San Diego-Mission Valley
Cost per mile up 19 percent from 1999.
San Francisco
Cost per mile up 16 percent from 1999.
Shorter route, cost per mile up 71 percent from 1999
Average up 22 percent from 1999.
Source: FY 2000 and 2001 FTA New Starts report (published in 1999 and 2000)

Local infighting over 'light' and 'heavy' transit resulted in this hybrid that runs lower capacity and slower vehicles in unimpeded, but less accessible, right-of-ways.  Its costs increased while its benefits, as measured by success in meeting the needs of consumers, decreased.  The hybrid product is mostly popular with the few for whom it is convenient and/or those who've had little exposure to other urban transit systems. 

One of the first, and largest, 'light' rail systems in the U.S. is in Portland.  In the commercial/business heart of the city, 2-car trains run on existing streets in designated/reserved lanes, sometimes on closed streets for short distances when ample right of ways are present.  The beauty of light rail is its ability to be easily accessible to patrons and to provide convenient access to final destinations.  This urban core implementation of the Portland system is by far its most popular feature. 

Light rail implemented in a heavy rail infrastructure.
Portland then extended this 'light' system miles into the metro area, though mostly in segregated right of way, to questionable success.  While Portland transit fans proudly tout their system, the ridership level doesn't indicate a success, with less than 5% of Portland commuters using the system; this in a city with fewer express roadways than other cities of its size.  

With a metro population of 2.2 million and 52 miles of rail transit, it should have far more than 59,500 weekday commuters (119,000 boardings) riding its rails.  By comparison, the Boston transit system, serving roughly twice the population with 64 miles of urban rail (38 miles of heavy rail, 26 of light rail), transports 354,900 weekday riders each way (709,800 boardings).

For Portland, with a city population density half that of Boston, this may be the best it can achieve, as demand may be insufficient to justify heavy rail transit.  Yet, the cost for a light rail implementation in this manner has costs approaching that of heavy rail.  The speed of light rail would be better marketed to in-town commutes, but its implementation (meant to attract metro commuters) has made it less accessible, and therefore less convenient for the in-town market.   The attempt to attract metro Portland commuters was futile, as its speed is too slow to make up for the other inconveniences of giving up a personal vehicle.  Thus, it attracts only a narrow portion of its potential market and makes it a highly expensive system per passenger.

Light rail infrastructure was originally characterized by right of ways more closely integrated into existing street systems, though not necessarily in mixed traffic.  Elaborate grade separations, which are also obstacles to passenger access, are unnecessary and, though cross traffic inhibitors may have existed in prior times, today technological innovations permit road traffic signals to be triggered by approaching trams.   This signal control allows priority passage for these vehicles, virtually eliminating cross traffic as an issue.

Like Portland's implementation of light rail outside of its core, the GLX proposal in Boston has some of the standard features of heavy rail, segregated right of way and stations spaced at least a half mile apart.  It virtually gives up all of the wonderful features which make light rail attractive, while attempting to fill the shoes best left to another transit mode.  Both heavy and light rail should be recognized for their unique attributes and functions and used for the needs to which they best apply.   Both modes have their place and both should tie into Boston's current transit system.