Francis Scott Key Bridge (I-695) complete collapse after large ship hits it

[Beltway]

Given that they are dealing with two nations, and it is funded through a public-private partnership (P3), there were years of legal and political wrangling, especially from the Ambassador Bridge's owner, who fiercely opposed the project, that would account for it taking a long time.
I could cite all three of the Bosphorus Strait bridges -- with no piers in the water.
Here's a list of the main span lengths of the three Bosphorus Strait bridges in feet:
+ 15 July Martyrs Bridge (First Bosphorus Bridge): 3,524 ft
+ Fatih Sultan Mehmet Bridge (Second Bosphorus Bridge): 3,576 ft
+ Yavuz Sultan Selim Bridge (Third Bosphorus Bridge): 4,619 ft
They also have a downtown highway tunnel  and a downtown railroad tunnel under the strait -- those folks don't play!

Give M-85 or M-5 a drive out of downtown Detroit and get back to me on how much MDOT doesn't fuck around.

They have another crossing under construction.

The Great Istanbul Tunnel is one of Turkey's most ambitious infrastructure projects — an undersea marvel designed to connect the European and Asian sides of Istanbul beneath the Bosphorus Strait.

Key Features
+ Length: 6.5 km (4.0 miles), making it the longest Bosphorus tunnel once completed
+ Depth: 110 meters below sea level
+ Diameter: 19 meters, accommodating three levels:
+ Two for road traffic
+ One for metro rail
Transportation Integration
+ Links Istanbul's three airports: Atatürk, Sabiha Gökçen, and Istanbul Airport
+ Connects nine metro lines and 11 other railways
+ Expected to serve 1.3 million passengers daily, with rail capacity of 70,000 passengers per hour per direction
Construction Timeline
+ Announced: 2015
+ Construction began: 2018
+ Expected completion: 2028
Financing and Engineering
+ Estimated cost: $3.5-4 billion
+ Built under a build–operate–transfer model
+ Excavation uses one of the world's largest tunnel boring machines -- 83 meters long and 20 meters wide

This will be Istanbul's third Bosphorus tunnel, following the Marmaray rail tunnel and the Eurasia road tunnel, but it's the first to combine road and rail in a single structure.

https://www.yukselproje.com.tr/en/projects/3-deck-great-istanbul-tunnel

[Max Rockatansky]

Given that they are dealing with two nations, and it is funded through a public-private partnership (P3), there were years of legal and political wrangling, especially from the Ambassador Bridge's owner, who fiercely opposed the project, that would account for it taking a long time.
I could cite all three of the Bosphorus Strait bridges -- with no piers in the water.
Here's a list of the main span lengths of the three Bosphorus Strait bridges in feet:
+ 15 July Martyrs Bridge (First Bosphorus Bridge): 3,524 ft
+ Fatih Sultan Mehmet Bridge (Second Bosphorus Bridge): 3,576 ft
+ Yavuz Sultan Selim Bridge (Third Bosphorus Bridge): 4,619 ft
They also have a downtown highway tunnel  and a downtown railroad tunnel under the strait -- those folks don't play!

Give M-85 or M-5 a drive out of downtown Detroit and get back to me on how much MDOT doesn't fuck around.

They have another crossing under construction.

The Great Istanbul Tunnel is one of Turkey's most ambitious infrastructure projects — an undersea marvel designed to connect the European and Asian sides of Istanbul beneath the Bosphorus Strait.

Key Features
+ Length: 6.5 km (4.0 miles), making it the longest Bosphorus tunnel once completed
+ Depth: 110 meters below sea level
+ Diameter: 19 meters, accommodating three levels:
+ Two for road traffic
+ One for metro rail
Transportation Integration
+ Links Istanbul's three airports: Atatürk, Sabiha Gökçen, and Istanbul Airport
+ Connects nine metro lines and 11 other railways
+ Expected to serve 1.3 million passengers daily, with rail capacity of 70,000 passengers per hour per direction
Construction Timeline
+ Announced: 2015
+ Construction began: 2018
+ Expected completion: 2028
Financing and Engineering
+ Estimated cost: $3.5-4 billion
+ Built under a build–operate–transfer model
+ Excavation uses one of the world's largest tunnel boring machines -- 83 meters long and 20 meters wide

This will be Istanbul's third Bosphorus tunnel, following the Marmaray rail tunnel and the Eurasia road tunnel, but it's the first to combine road and rail in a single structure.

https://www.yukselproje.com.tr/en/projects/3-deck-great-istanbul-tunnel

Nice dodge on Detroit and MDOT.  Certainly took you long enough to reply.

[kphoger]

tunnel boring machines

I've heard those are boring.

[Max Rockatansky]

tunnel boring machines

I've heard those are boring.

This whole thread got all things boring once Beltway started on about his fictional tunnel ideas.

[Plutonic Panda]

Seems like more times than not with a few exceptions, Any new proposal for a tunnel in this country is fictional.

[Henry]

Michigan and Ontario show how bridge a busy shipping channel -- Gordie Howe International Bridge.
Cable-stayed bridge with no piers in the water, 2,900 foot main span, minimizing environmental impact, eliminating the risk of ship collisions.

You do realize that this would be impossible with the new Key Bridge? Ergo, very strong dolphin protection is a must. If this were 1980 when the Sunshine Skyway bridge went down, I'm betting that you would've also argued in favor of a tunnel across Tampa Bay, given how you always say the same is needed here as well.