Alto Tunnel Transportation Study Information

 The Marin County Nonmotorized Transportation Pilot Program’s Advisory Committee recently recommended $850,000 for an Alto Tunnel study. On April 17, 2007, the Marin County Board of Supervisors will make a final decision as to if this important study is funded. 

The study will be very complex and will include analysis of many issues including: 

*  All possible alternatives for travel between Mill Valley and Corte Madera as well as the costs to construct these different projects

*  The potential for bicycle and pedestrian use for all of the different alternatives

* An analysis of particular issues related to the tunnel that are necessary to determine the construction costs and methods including a preliminary engineering assessment of the tunnel. 

Some of the Pilot Program moneys should also be used for public meetings to ensure that all stakeholders are involved throughout the process. 

This study has to be completed if the Alto Tunnel will ever be reconstructed. An alternatives analysis is always the first step in any major public works project. 

The County of Marin did an exploration of the northern portal of Alto Tunnel in 2001 and found that the first 170 feet was passable, but beyond that, low-grade concrete blocked the team from entry – therefore, they need to do an engineering exploration to truly assess the condition of the tunnel, including how much it would cost to repair it, and what engineering methods would be used. 

The cost of the Alto Tunnel study will never be as low as it is now! Just seven years ago, the cost was $300,000. It is vital that these Pilot Program funds are used so that we can move forward and get this project rolling! There are no other sources of planning funds that can be used for this project. We must use these discretionary dollars. 

No one knows exactly how much it would cost to re-open the Alto Tunnel, which is one reason that we need the County of Marin to fund the Alto Tunnel study out of the federal Pilot Program funds. Prior “informal” estimates of the cost of rehabilitating the Alto Tunnel have ranged from $10 to $20 million dollars. The $850,000 for the study is simply part of that construction costs. 

These numbers all seem large, but consider that widening 101 mostly within its current footprint from Novato to Petaluma will cost around $750 million (that's ¾ billion dollars) for approximately 16 miles of freeway.  

Please support the use of Pilot Program funds for the Alto Tunnel. To take action in support of the Alto Tunnel, please click here.