Bike group slams report on Mill Valley-Corte Madera link

Richard Halstead
Marin IJ, January 26, 2010

The Marin County Bicycle Coalition presented the Board of Supervisors on Tuesday with a scathing critique of a draft report that evaluates the relative merits of three bicycle/pedestrian routes connecting Mill Valley and Corte Madera.

Using federal funds earmarked for promoting walking and biking, the county commissioned Benecia-based Alta/LandPeople to study the feasibility of three routes: Camino Alto/Corte Madera Ave.; Horse Hill and Alto Tunnel.

"We feel the consultants who prepared this report have not fulfilled their responsibility under their $225,000 contract," said Andy Peri, the coalition's advocacy and outreach coordinator. "We want to make sure the county gets its money's worth."

Peri and others addressed the issue during the public open time segment of the supervisors' weekly meeting, because the item was not on the agenda. The coalition's rebuttal was presented as a 64-page document with four appendices, "because we found a lot of areas that are in need of being addressed," Peri said.

The coalition's areas of greatest concern, Peri said, are the report's cost and use estimates for the Alto Tunnel route. The report estimates the Alto Tunnel route would cost $40 million to $52 million and it projects that an average of 1,863 bicyclists and 466 pedestrians would pass through the tunnel daily.

The coalition says the cost estimate is far too high while the estimate of users is too low. One of the reasons the cost estimate is inflated, the coalition says, is because the report uses Cal Park Hill Tunnel cost as a basis. The Cal Park tunnel, between San Rafael and Larkspur, was designed to accommodate the new commuter train that will run between Cloverdale and Larkspur, which required costly features that won't be needed in the Alto Tunnel, the coalition says.

The cost estimate was arrived at by calculating the number of people riding bicycles and walking on pathways on either side of the tunnel and then dividing this number in half, the coalition says. But the coalition asserts that based on other studies throughout the United States, it is well known that bicycle and pedestrian numbers increase, not decrease, when facilities are connected.

The tunnel is 16 feet wide, 20 feet tall and approximately 2,200 feet long, and served as a single-track rail tunnel for nearly 90 years. In 1958, there was a substantial upgrade to the northern portal, which remains intact and in good condition today.

The tunnel remained open until 1971, when bulkheads were added at each portal to prevent entry. In 1975, a plug extending approximately 125 feet was added near the north end of the tunnel and in 1981, there was a collapse at the southern portal. The southern portal area was stabilized in 1982 with gravel and earth fill. The middle 1,600 feet of the tunnel remains sealed off.

The coalition asked supervisors to make sure that the draft report is revised and a public hearing held to evaluate it before a final version is approved. The coalition also wants supervisors to expand the study's technical advisory committee to include the Marin County Bicycle Coalition, Transportation Alternatives for Marin and various neighbors from Mill Valley and Corte Madera. The advisory committee consists of representatives from the county of Marin, Mill Valley, Corte Madera and the Transportation Authority of Marin.

Randy Anderson, who is coordinating the project for Alta/LandPeople, declined to comment. He said any response to the coalition's criticisms must come from the county of Marin. There was no response from supervisors to the coalition's request at Tuesday's meeting.