* Guide for the Preservation of Highway Tunnel Systems:
http://www.trb.org/main/blurbs/173393.aspx
* National Cooperative Highway Research Program:
http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_syn_482.pdf
Recommended Posts
* Guide for the Preservation of Highway Tunnel Systems:
http://www.trb.org/main/blurbs/173393.aspx
* National Cooperative Highway Research Program:
http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_syn_482.pdf