CAHSR’s Preliminary Alignment on the Peninsula
For the past six months, I’ve been working with AutoCad, Google Earth, and the California High Speed Rail Authority’s website with the goal of creating an up-to-date .kml file of the current proposed route for the CHSR, with specific attention to the alternative analysis. Starting with today’s post, and continuing for the next couple months, I will be presenting the 2010 proposed alignments and analyzing the alternatives that the CHSRA will carry forward. The purpose of these kml files is not to show the exact route but rather to help gain a general overview of the alignment alternatives and the types of structures necessary for each alternative.
As a native San Franciscan, I thought it would be best to start with San Francisco and head south during this review of the California High Speed Rail alignments. This section has been a major talking point as a part of the entire California High Speed Rail debate. Due to prohibitive costs,the High Speed Rail Authority has been reluctant to bury a significant portion of the alignment,much to the dismay of local communities who fear not only lowered property values, but also the prospect of their communities being “divided in two” by the high speed rail right of way.
Along with the Los Angeles to Anaheim section, this section of the alignment is unique in that,at this point in the design process, there is only one horizontal alignment under consideration;that is, there is only one right-of-way path. In this section, alignment alternatives along I-280 and US-101 were ruled out due to design challenges. An I-280 alignment would have been too curvaceous to allow for the Prop 1A guaranteed 2 hours and 40 minutes between LA and SF and the US-101 path would be too expensive due to the multiple overpasses already in place on the freeway. Instead, the CHSRA chose to pursue the current Caltrain right-of-way as the preferred horizontal alignment.
That is to say, the Caltrain alignment is not without its design challenges. The right-of-way in some parts of the peninsula is only 50’ wide, much narrower than the 91’ expected to be necessary for even the narrowest of high speed rail structures. Downtown San Mateo and Redwood City, in particular, present difficult engineering challenges due to their narrow right-of-ways. As of September 2010, the HSR Authority settled on three designs. Design A includes more aerial structures and is likely to meet the most opposition from Peninsula cities. Design B places many of the aerial structures below grade in trenches or tunnels. Design B1, labeled B1 because it is a variation on Design B, places even more track below grade.
On the corridor, HSR will be sharing the right-of-way and the four tracks with an electrified Caltrain, meaning that the HSR will be restricted to 90mph on the Peninsula. The Authority is also choosing between a possible “Mid-Peninsula Station” in Redwood City, Palo Alto, or Mountain View. Either one or none of these stations will be selected.
You are free to view this map but please know that it is not affiliated in any way with the California High Speed Rail Authority, and Sam only used publicly available information to compile it. If you’d like to share it, please attribute it to Sam Levy or Wilshire/Vermont. He spent a lot of time getting this thing together. -Karl
Sorry about the ads. WordPress won’t host a .kmz file.
Posted on March 22, 2011, in High Speed Rail, San Francisco Bay Area and tagged Caltrain, High Speed Rail, SamTrans, San Francisco, San Francisco Bay Area, San Jose, Transportation. Bookmark the permalink. 2 Comments.