Here are 3 pages from the section, Tunnel Excavation Report, pages 6 (map) & 361-362.
4.2 miles of bored tunnel
.7 miles of cut and cover tunnel
1.4 miles of at-grade segments.
Total: 6.3 miles
Map of the dual-bore tunnels (see Excavation Report + map pp.361-362)
South Portal: It will begin immediately North of Hellman Ave.–In Alhambra and NOT in Los Angeles. However, the at-grade section will begin just south of the 10 Freeway.–in Monterey Park.
There will be an entrance & exit to the south 710 from Valley Blvd.–as it is now. (No entrance/exit from the tunnels to Valley Blvd.) In other words, it will not change the traffic pattern of today and may, in fact, increase traffic on Valley Blvd.
The map shows an interchange with the 710/10 freeways. I am assuming this means motorists will be able to travel north into the 710 tunnel and exit to the 10 while traveling south.
North Portal: The portal will be immediately south of Green St.
There will be NO SURFACE STREET entrances or exits. There will, however, be 6 freeway entrances/exits:
to/from the 134 (2)
to/from the N. 210 (La Canada) (2)
to/from the E. 210 (Pasadena) (2)
This is going to make for some exciting traffic patterns at the next (surface street) entrance/exit of the above freeways.
Section 3.1.1 Bored Tunnels
The outside diameter of the final lined tunnels will be abt. 58 1/2′. However, the outside diameter of the excavated tunnels will be abt. 60′. (I believe this is the number we should use).
Section 3.1.3 Construction Portals
This is the area that is needed and must be excavated just to get the tunnel boring machines and construction materials in place before boring can begin.