The promised "stem to stern'' safety review of the Big Dig is being hindered by the design of the Ted Williams Tunnel, which makes access to thousands of bolts impossible.
The Boston Herald reports inspectors can't test the strength of about 4,000 epoxy bolts supporting the tunnel's ceiling because there is no crawl space.
The review was promised by former Gov. Mitt Romney following a ceiling collapse in a connector tunnel in July 2006 that killed a Boston woman.
Gary Klein of Wiss, Janney, Elstner Associates, which is leading the review, says the bolts do not appear to pose a safety threat because of redundancies built in to the ceiling's design.
Big Dig officials say lighter ceiling panels and the proper epoxy were used in the Ted Williams Tunnel, compared to the tunnel where the collapse occurred.
This program aired on February 20, 2008. The audio for this program is not available.