I doubt that many who see this will be building a real road tunnel any time
soon.
But for sheer scope and depth of cover its worth a look.
Blackhole for some. Interesting flick through for others.
Even has a picture of a black hole, road tunnel style.


Technical manual for the design and construction of road tunnels  -

Online by section

     http://www.fhwa.dot.gov/bridge/tunnel/pubs/nhi09010/index.cfm

702 page 50 MB PDF

     http://www.fhwa.dot.gov/bridge/tunnel/pubs/nhi09010/tunnel_manual.pdf

Blackhole fwiw:
http://www.fhwa.dot.gov/bridge/tunnel/pubs/nhi09010/02a.cfm#fig2_7


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