After five years of construction, the $880 million, 19-mile southeast train started hauling commuters Monday between metro Denver's two major employment centers - downtown and the Denver Tech Center.
Thus, it cost about $46.3 million per mile.
The lane expansion part of T-Rex, over a similar number of miles cost $795 million, about $42 million per mile.
The per mile costs of both parts of the T-Rex project were high (although both parts of the project were on time and under budget). This isn't too surprising, as the expansion was through a densely populated urban area, while maintaining traffic flows, rather than virgin territory.
The E-470 toll road cost $1,200 million and runs for 47 miles, a cost of about $25.5 million per mile, without the constraints associated with T-Rex.
The Northwest Parkway toll road is 11 miles long. The Daily Camera reported that it was a $190 million construction effort, but the 2004 annual report of the Northwest Parkway's governing body indicates that $413 million in bonds had to be issued for the project, which is $37.5 million per mile. I suspect that the construction costs cited by the Daily Camera exclude design, engineering and land acquisition costs. It carries traffic of 11,428 cars a day as of October 2006.
The Southwest Light Rail line has traffic of about 18,000 trips per day. Southeast light rail will probably add more traffic than the Southwest light rail line did.
Bottom Line: Light rail ain't cheap. But, on a per trip basis, it is comparable to, or a better deal than, toll roads, and on toll roads, people also have to buy their own vehicles to use the system.