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One of the greatest impacts the HSR will have one the peninsula will be determined by the 'grade' design for the rail. 'Grade' refers to the height of the ground on which the train tracks are located. The four alternatives include:

• below-grade (tunnel)
• below-grade (trench only) [Box Trench]
• below-grade hybrid (tunnel+trench) [Hat Trench]
  • dual stack (Caltrain/freight on top/HSR Bottom)
  • four track (side by side)
  • two track (Caltrain/freight/HSR shared track) - New idea!
    • Phase One: Top Trench/Tunnel
    • Phase Two: Bottom Tunnel (when capacity needed and money available)
• at-grade (same level as the street)
• above-grade (mound)
• above-grade (stilts) aka Aerial

There are four different rail services which need to be considered when selecting the grade design. These include:

• Local CalTrain service
• Baby Bullet CalTrain
• Freight
• High-Speed Rail

Some of the constraints that need to be accommodated in any decision include:

• Freight exhaust, which has diesel engines
• Freight gradation (slope) of 1%-3%. Some debate is taking place with regards to the exact number.
• CalTrain electrification
• No crossings are allowed with High-Speed Rail
• Cost
• Community Impact

One of the biggest challenges, according to the "California High-Speed Train Project Anaheim to Los Angeles Section - Alternatives Analysis Report" is Constructability. Part of the issue has to do with the need to build shoofly (temporary by-pass) near the construction area. Here is a brief example of what a shoofly looks like.

Sample of Rejection of Cut-and-Cover Tunnel alternative according to Alternatives Analysis. (Page 49-50)

"Cut and cover tunnel is extremely difficult to construct below existing railroad while maintaining rail operations. This section of the corridor currently carries over 40 Metrolink and Amtrak trains per day, with service expanding to nearly 100 trains per day by the forecast year. Two tracks without operating constraints are required during construction to be able to maintain current levels of service, but this is not possible within existing ROW. At best, one track can be kept operating without speed restrictions during construction, or two tracks with speed restrictions due to the proximity of construction activities and equipment. Construction activities will need to be concentrated during nighttime to minimize impacts to rail operations, but such activity would have significant noise impacts on surrounding residential communities. Additional ROW could alleviate constructability issues, but would compromise purpose of cut-and-cover tunnel option (to minimize ROW impacts). Complicated logistics will result in disposing of the earth removed during construction activities. If the earth removed is loaded into a train for hauling to a disposal site, a loading facility and new temporary industrial track will need to be constructed. This loading facility may require additional ROW to construct and operate. It will also have significant noise, vibration and light impacts. If the earth removed is hauled away on truck, there are significant roadway, traffic levels, and air quality and noise impacts. Would require complete replacement of existing Lincoln Avenue undercrossing, as it would be in path of HST structure. This is not feasible without closure of Lincoln Blvd for extended period (large traffic impacts) or extensive ROW takes (which would compromise purpose of cut-and-cover tunnel option – to minimize ROW impacts)."

Grade Selection DIY

Two files are attached below. The first is a Design Criteria document, which outlines the Evaluation Criteria which CHSRA uses. The second is a Do-It-Yourself Grade Evaluation form. It takes the Criteria in the first document and gives you or a group a form to fill in. Feel free to add criteria. The focus of the CHSRA's criteria does miss some local impact questions, for example a city perspectives (community divide/unite) and local economic impacts.