Since October, when Governor Cuomo announced the fast-tracking of the Tappan Zee Bridge replacement project, New York State has used the allegedly prohibitive cost of transit to justify omitting transit from the bridge. In the draft environmental impact statement for the project released in January, the state claimed that a bus rapid transit (BRT) system in the I-287 corridor would cost $4.5-$5.2 billion, putting the price tag on par with the cost of building two new bridge spans. Yet, in 2009, the state estimated that a bus rapid transit system through the corridor would range between $900 million and $2.5 billion. The discrepancy caused many raised eyebrows and double-takes.

Now, Tri-State Transportation Campaign may have discovered why the state’s figures are so high. In a press release issued today [pdf], the Campaign announced that its preliminary analysis of state documents—received 129 days after the filing of a Freedom of Information Law request prompted by this unexplained spike in cost—suggests that the state never analyzed the price of a simple BRT only option, instead relying on outdated information from a significantly larger project.

The state’s estimate for BRT appears to be based on figures from the old Tappan Zee Bridge/I-287 Corridor Project, a study that was terminated when Governor Cuomo fast-tracked the Tappan Zee Bridge replacement. The cost documents predate October 2011, when the new project was announced.

The use of these old project numbers might explain the state’s outsized cost estimates for a simple BRT system, since the study contemplated an elaborate I-287 corridor that made provisions for BRT, commuter rail transit (CRT), and climbing lanes for trucks. A sample cross section of the Rockland corridor before and after the expansion can be seen below.

The high cost estimates for such an extensive project make sense: it clearly required a lot of work. However, most of this build-out was due to the inclusion of a climbing lane and commuter rail accommodations, neither of which is necessary for a bus rapid transit system in the I-287 corridor. Each scenario comingles costs for all elements of the project. Accordingly, many of the high-cost construction aspects of the older project, like retaining walls, rock blasting, infill, interchange additions, and tunnels, likely would not be necessary in a slightly wider corridor that could accommodate buses. These extraneous construction costs could help explain why New York State’s cost estimate for BRT is approximately five times the industry average.

But many of these costs are irrelevant to the installation of a lean, cost-effective enhanced bus service system—one that is not only inexpensive and easy to implement, but also easily integrated into a fully built-out corridor (if and when funding permits).

The Tappan Zee Bridge project is too important to the Lower Hudson Valley to proceed on the basis of these questionable cost estimates. The state should complete a thoroughly-documented cost analysis of a bus rapid transit system in the corridor that includes simple bus improvements in the short term and more enhanced bus rapid transit in the future.