AARoads Forum

National Boards => Bridges => Topic started by: tolbs17 on January 14, 2022, 09:48:21 PM

Title: How do you measure the height of this bridge?
Post by: tolbs17 on January 14, 2022, 09:48:21 PM
I want to know how high this bridge is. If it's lower than 16 feet, then I-587 can't be signed on it.

I-40 ALT
https://maps.app.goo.gl/K7JK21sMxjaLk64S7
Title: Re: How do you measure the height of this bridge?
Post by: Max Rockatansky on January 15, 2022, 12:06:42 AM
Whip out a ruler and measure.  Donít forget the two inch rule.
Title: Re: How do you measure the height of this bridge?
Post by: SkyPesos on January 15, 2022, 12:25:14 AM
I want to know how high this bridge is. If it's lower than 16 feet, then I-587 can't be signed on it.

I-40 ALT
https://maps.app.goo.gl/K7JK21sMxjaLk64S7
What? Plenty of overpasses with a clearance of between 14 and 16 ft exist on interstate highways.
Title: Re: How do you measure the height of this bridge?
Post by: tolbs17 on January 15, 2022, 12:38:21 AM
I want to know how high this bridge is. If it's lower than 16 feet, then I-587 can't be signed on it.

I-40 ALT
https://maps.app.goo.gl/K7JK21sMxjaLk64S7
What? Plenty of overpasses with a clearance of between 14 and 16 inches exist on interstate highways.
From Wikipedia...

https://en.m.wikipedia.org/wiki/Interstate_Highway_standards#:~:text=Vertical%20clearance%3A%20The%20minimum%20vertical,for%20extra%20layers%20of%20pavement.&text=The%20cross%20bracing%20of%20truss,17.5%20feet%20(5.3%20m).

Quote
Vertical clearance: The minimum vertical clearance under overhead structures, such as bridges, is 16 feet (4.9 m), including both paved shoulders and an allowance for extra layers of pavement. Through urban areas, at least one routing is to have 16-foot (4.9 m) clearances, but others may have a lesser clearance of 14 feet (4.3 m). Sign supports and pedestrian overpasses must be at least 17 feet (5.2 m) above the road, except on urban routes with lesser clearance, where they should be at least 1 foot (30 cm) higher than other objects. The cross bracing of truss bridges has a special additional clearance requirement of 17.5 feet (5.3 m).
Title: Re: How do you measure the height of this bridge?
Post by: CtrlAltDel on January 15, 2022, 01:04:36 AM
Plenty of overpasses with a clearance of between 14 and 16 inches exist on interstate highways.

I'm not so sure that's true.  :-D
Title: Re: How do you measure the height of this bridge?
Post by: Max Rockatansky on January 15, 2022, 01:13:20 AM
Plenty of overpasses with a clearance of between 14 and 16 inches exist on interstate highways.

I'm not so sure that's true.  :-D

Itís not the size of the bridge that counts, itís how you use it.
Title: Re: How do you measure the height of this bridge?
Post by: tolbs17 on January 15, 2022, 01:18:04 AM
Reason why I asked this question is because LM117 said they're too low.
Title: Re: How do you measure the height of this bridge?
Post by: wanderer2575 on January 15, 2022, 01:20:11 AM
I knew this was a tolbs17 thread just by the topic name.
Title: Re: How do you measure the height of this bridge?
Post by: Max Rockatansky on January 15, 2022, 09:07:20 AM
Reason why I asked this question is because LM117 said they're too low.

Did you compare your bridge heights?  Some bridges donít look the same you know.
Title: Re: How do you measure the height of this bridge?
Post by: SkyPesos on January 15, 2022, 09:27:19 AM
Plenty of overpasses with a clearance of between 14 and 16 inches exist on interstate highways.

I'm not so sure that's true.  :-D
I forgot weíre talking about highways for cars here, not highways for cats  :-D
Title: Re: How do you measure the height of this bridge?
Post by: jeffandnicole on January 15, 2022, 11:46:19 AM
This may be one of my favorite.  295 South at the Aljo curve. Right lane (which is the far right lane against the barrier) during construction...13' 7". No advanced warning. Some truckers get a little nervous when they approach this overpass when they see the signs at the last moment. 
https://maps.app.goo.gl/1yfP53jkopSJzc7j7



I want to know how high this bridge is. If it's lower than 16 feet, then I-587 can't be signed on it.

I-40 ALT
https://maps.app.goo.gl/K7JK21sMxjaLk64S7

Look up an online database for bridges. They usually include a clearance height.  If they want to give a highway interstate status, exceptions can be made.
Title: Re: How do you measure the height of this bridge?
Post by: tolbs17 on January 15, 2022, 04:47:04 PM
Or NCDOT can be like SCDOT or TxDOT and mount bridge clearances on the overpasses. Just saying that because I can't find a map of how high and low the bridges are in North Carolina.
Title: Re: How do you measure the height of this bridge?
Post by: SteveG1988 on January 16, 2022, 03:49:36 PM
I want to know how high this bridge is. If it's lower than 16 feet, then I-587 can't be signed on it.

I-40 ALT
https://maps.app.goo.gl/K7JK21sMxjaLk64S7
Some states don't post certain heights, like if it is unposted in IL on like US30 it is 13-6 or above.
Title: Re: How do you measure the height of this bridge?
Post by: dlsterner on January 16, 2022, 04:27:36 PM
I want to know how high this bridge is. If it's lower than 16 feet, then I-587 can't be signed on it.

I-40 ALT
https://maps.app.goo.gl/K7JK21sMxjaLk64S7

It's simple.
You're welcome.   :bigass:
Title: Re: How do you measure the height of this bridge?
Post by: Big John on January 16, 2022, 04:38:46 PM
^^ Reminds me of this: https://www.gocomics.com/calvinandhobbes/1986/11/26
Title: Re: How do you measure the height of this bridge?
Post by: dlsterner on January 16, 2022, 04:45:26 PM
^^ Reminds me of this: https://www.gocomics.com/calvinandhobbes/1986/11/26
Yes, that very comic strip is where I got the inspiration for my post   :bigass:
Title: Re: How do you measure the height of this bridge?
Post by: triplemultiplex on January 19, 2022, 12:35:19 PM
How do you measure the height of this bridge?

(https://static.grainger.com/rp/s/is/image/Grainger/49LX72_AS01?hei=536&wid=536&$adapimg$=)

Alternatively, the company I work for can do it with LiDAR.  Vertical Clearance Measurement for overhead structures is sometimes a deliverable for our customers.