# Cost of a New cape Cod Bridge (vs. Tunnel)? **URL:** \ **Category:** Factual Questions\ **Created:** [November 3, 2015, 11:39am UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510 "2015-11-03T11:39:23Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [November 3, 2015, 11:39am UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/1 "2015-11-03T11:39:23Z")
As a frequent visitor to Cape Cod, i wonder when it will be necessary to replace the two traffic bridges. They were both completed in 1934, and are at the end of their lives. For a bridge, the span is about 0.7 mile. For a tunnel, you need about another 0.3 miles for approaches. The canal is only about 40 feet deep, and there is no real bedrock. Cape Cod is (essentially) a big sand bar, so cutting a trench and burying a tube is probably the easiest option. In any case, which option would cost the least? i vote for a tunnel. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [November 3, 2015, 12:25pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/2 "2015-11-03T12:25:16Z")
> [@ralph124c](#): > > As a frequent visitor to Cape Cod, i wonder when it will be necessary to replace the two traffic bridges. They were both completed in 1934, and are at the end of their lives. For a bridge, the span is about 0.7 mile. For a tunnel, you need about another 0.3 miles for approaches. The canal is only about 40 feet deep, and there is no real bedrock. Cape Cod is (essentially) a big sand bar, so cutting a trench and burying a tube is probably the easiest option. In any case, which option would cost the least? i vote for a tunnel. Maybe they should have a tunnel to keep the road open during a storm… The bridges close in strong wind, as vehicles would be blown out of their lanes, and the bridges are vulnerable to storm damage. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [November 3, 2015, 12:56pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/3 "2015-11-03T12:56:56Z")
Apparently MassDOT is [soliciting bids to build & operate](https://www.bostonglobe.com/business/2015/05/24/state-officials-advance-plans-for-new-cape-bridge/KgXj6rSejGVrWihhsgtmxO/story.html) a third bridge next to the Sagamore Bridge. The new bridge would be a toll bridge (at least initially) and would handle Cape-bound traffic, while the Sagamore would become mainland-bound only. Also, from the above article: > [@](#): > > The Army Corps, meanwhile, is embarking on its own review of the existing bridges to determine whether the aging spans need to be renovated or replaced. If the Army Corps moves ahead with fixes, however, the focus would not be on adding lanes to alleviate traffic. A decision on that front would not come until at least 2017, and DePaola said he does not want to wait much longer. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [November 3, 2015, 12:57pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/4 "2015-11-03T12:57:45Z")
> [@ralph124c](#): > > … cutting a trench and burying a tube is probably the easiest option. Cutting a trench gets a bit more complicated when it has to cross an active canal full of water. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [November 3, 2015, 1:10pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/5 "2015-11-03T13:10:57Z")
Gee, you’d think they’d have plenty of revenue from all those Cape Cod Tunnel permits they sell > **[cape cod tunnel permits images - Bing](http://www.bing.com/images/search?q=cape%2Bcod%2Btunnel%2Bpermits%2Bimages&view=detailv2&qpvt=cape%2Bcod%2Btunnel%2Bpermits%2Bimages&id=64462F6B83D776503A613AEBE2ECB18ECED7C94A&selectedIndex=0&ccid=N6lduCDU&simid=608014245704043519&thid=OIP.M37a95db820d406f43f67f3afb1d9578do0&ajaxhist=0)** > > Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you. > **[cape cod tunnel permits images - Bing](http://www.bing.com/images/search?q=cape%2Bcod%2Btunnel%2Bpermits%2Bimages&view=detailv2&qpvt=cape%2Bcod%2Btunnel%2Bpermits%2Bimages&id=5D69FEC6A7AEB935E160F13276253D1D2B57B58A&selectedIndex=4&ccid=uvsYCtkE&simid=607992637723445440&thid=OIP.Mbafb180ad90471980b319aa0b4863b45o0&ajaxhist=0)** > > Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you. ---
**Author:** ![BrotherCadfael](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)\ **Post date:** [November 3, 2015, 1:16pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/6 "2015-11-03T13:16:59Z")
> [@MikeS](#): > > The new bridge would be a toll bridge ( **at least initiall** y) And you \*believe \*that??? ---
**Author:** ![NeonMadman](https://avatars.discourse-cdn.com/v4/letter/n/58f4c7/32.png) [@NeonMadman](https://boards.straightdope.com/u/NeonMadman)\ **Post date:** [November 3, 2015, 2:42pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/7 "2015-11-03T14:42:24Z")
> [@MikeS](#): > > The new bridge would be a toll bridge (at least initially) The Mass. Turnpike was supposed to be a toll road - at least initially. It still is, 60 years later. Once Massachusetts starts getting a cash flow, they aren’t about to give it up. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [November 3, 2015, 3:01pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/8 "2015-11-03T15:01:26Z")
I thought he meant one which crossed the bay (from say Plymouth)… ---
**Author:** ![puddleglum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puddleglum/32/137_2.png) [@puddleglum](https://boards.straightdope.com/u/puddleglum)\ **Post date:** [November 3, 2015, 3:28pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/9 "2015-11-03T15:28:16Z")
Bridges are usually about half the cost of tunnels but need refurbishment sooner. Tunnels are usually built either for security purposes if the river is near a navy base, or if the nearby land is extremely expensive such as New York since bridges have a larger footprint on land. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 3, 2015, 4:19pm UTC](https://boards.straightdope.com/t/cost-of-a-new-cape-cod-bridge-vs-tunnel/736510/10 "2015-11-03T16:19:50Z")
Fill in the canal.