Number of bridges in Detroit

**Patrick** · January-12-10, 08:56 PM

Anybody know many bridges there are in Detroit? I am talking traffic, foot, parkland and others. Any idea? DC has about 200 while Pittsburgh has 446 and Venice has 443.

MichMatters · January-12-10, 10:19 PM

I'd not even feel comfortable taking a guess, but since MDOT has jurisdiction over [[road) bridges, that'd be the best place to start. Here are some regional contacts for MDOT:

MDOT - Metro Region:

18101 W. Nine Mile Rd., Southfield, MI 48075

248-483-5100

peekb@michigan.gov

morosir@michigan.gov

MDOT - Detroit Transportation Service System:

1400 Howard St, Detroit, MI 48216

313-965-6350

**Gsgeorge** · January-13-10, 01:55 AM

don't forget all the train bridges & underpasses.

**Gistok** · January-13-10, 03:24 AM

Geeze that sounds like a rather difficult list to compile, unless you're only counting freeway bridges.

Of major bridges, I would say 4... Ambassador.... MacArthur [[Belle Isle), I-75 Rouge River Bridge, and the I-94 Dequindre Yard Bridge.... but I'm not including other freeway/train bridges... which would bring the count way up there.

And then there's the bridges that cross over canals on the far east side [[near Alter Rd.)... and the bridges on Belle Isle and Rouge Park... and those on the Dequindre Cut.. even Woodward & 8 Mile count as 3 bridges [[Woodward and the 2 bridges on either side of it that count as service drives over 8 Mile Rd.).

Lots and lots of bridges... with a number that will likely be difficult to determine...

**Meddle** · January-13-10, 03:50 AM

My guess would be well over a thousand when you count all the crosswalks over freeways and everything that crosses a canal, creek, tributary, etc. The Rouge River basin alone is fairly expansive and you'd have to account for all of the lower east side and delray.

There used to be some crosswalks over surface roads near schools also.

There's around 8 or 9 just at the Southfield/Jeffries interchange and I'm sure that number is duplicated at most major interchanges like 75/94, 75/Lodge, 94/Lodge.

**luckycar** · January-13-10, 07:16 AM

Google Earth and start at one part of town and start counting.Should be about 1,000.SE MI,2,000.Just a w.a.g.

**DetroitPlanner** · January-13-10, 07:21 AM

One geography geek I knew counted 100 bridges along I-94 within the City of Detroit alone. The difficulty you will have in collecting data by geography will be that the State, County, City, railroads, and private entities [[think Matty or ped bridges connecting buildings) all own bridges. Not all of it is public data. If you go asking questions like 'how many bridges are there in Detroit' you are at best likely to get wildly different answers. At worst? You will get locked up on suspiscion on being a terrorist.

Depending on how you define a bridge, you will also get varying answers. Many of the footbridges or street bridges that cross streams are not considered bridges by the feds, but rather culverts. Are freway ramps flying over interchanges bridges? If so do you count each one individually? Whow about a ramp that is land-bridge-land-bridge-land? Is that two or one??

You can check SEMCOG's site, there is a bridge component to the long range plan; but I don't know if it breaks the total numbers down by mode and geography. There are 3,500 bridges over 20 feet long by its definition in its region.

**RO_Resident** · January-13-10, 11:21 AM

As of a couple of years ago, there were ~635 bridges in Detroit.

**Meddle** · January-13-10, 01:26 PM

635 might possibly be the number over freeways, but certainly not the total number of all bridges of all types within the city.

Many of the footbridges or street bridges that cross streams are not considered bridges by the feds, but rather culverts. Are freway ramps flying over interchanges bridges? If so do you count each one individually? Whow about a ramp that is land-bridge-land-bridge-land? Is that two or one??

In my mind, over 10 feet is a bridge, no matter what it crosses. Culverts are a pipe buried in dirt. Freeway ramps, yes and each individual. That's why I said 8 or 9 at Southfield/Jeffries. For your land/bridge/land question, look at the Chesapeake Bay Bridge Tunnel.

At the 10 foot threshold, that 3,500 number would surely rise, possibly double.

**waz** · January-13-10, 01:42 PM

What about the old Packard Plant pedestrian walkway across Grand Blvd.? Does that count?

**Crystal** · January-13-10, 01:57 PM

Two fun sites are:

http://bridgehunter.com/

http://www.historicbridges.org/

Retroit · January-13-10, 03:57 PM

And don't forget that pedestrian air bridge over Larned between the Guardian Bldg and the Michigan Consolidated Gas Bldg.

Anyone know the history of this bridge? Why it was built? Were there ever plans to build more of these bridges? What are the benefits/disadvantages of connecting buildings this way?

**RO_Resident** · January-13-10, 03:57 PM

Originally Posted by Meddle

635 might possibly be the number over freeways, but certainly not the total number of all bridges of all types within the city.

In my mind, over 10 feet is a bridge, no matter what it crosses. Culverts are a pipe buried in dirt. Freeway ramps, yes and each individual. That's why I said 8 or 9 at Southfield/Jeffries. For your land/bridge/land question, look at the Chesapeake Bay Bridge Tunnel.

At the 10 foot threshold, that 3,500 number would surely rise, possibly double.

The 635 bridges includes road over water, road over road, road over rail, rail over road, ped, misc [[plazas, buildings), and non-motorized bridge structures that are owned by public agencies in within the city limits of Detroit. The figure does not include the Ambassador Bridge.

And as DetroitPlanner states a structure is only considered a bridge if the span is >= 20 feet. Otherwise it is a culvert. This is to ensure uniformity for inspections and funding across the country. I don't make the rules...

**waz** · January-14-10, 07:42 PM

My commute takes me on I-75 through it's entire run in Detroit. I decided to take an unoffical count on the way home today and came up with 93 bridges that I either passed under or that took me oversomething. This includes, car, pedestrian and railroad bridges. I also counted both spans of boulevards, e.g. 8 Mile road.