A $4.5 million "stem to stern" review of Boston's Big Dig underground highway system has concluded that the project was well-built overall, but still needs some repairs.

According to The Associated Press, Massachusetts Gov. Mitt Romney ordered the review after a woman was killed last summer when concrete ceiling panels in one of the tunnels collapsed onto her car.

While the review says most of the $14 billion-plus project is in good shape, it does call for improvements in the fire-detection system and the backup generators for lighting.