Subscribe for full online access and get...
- Full, instant access to all stories
- Customised email alerts straight to your inbox
- Monthly print magazine
For the best possible experience using our website we recommend you upgrade to a newer version or another browser.
What is almost certainly the most expensive and complicated interchange in the history of world highways is beginning to take shape in the centre of Boston. A three dimensional nightmare of tunnels and viaducts, the South Bay interchange, has to be completed within three years, at a cost of $397M (£244M), while keeping 190,000 vehicles a day flowing freely through the centre of the site.