How to Modify a Traffic Signal Base Within an ADA Ramp?

[raydefan]

I am working on road rehab project where several ramps need to be replaced to conform to ADA standards. There are a few ramps where existing traffic signals would be within the side slope portion of the new ramp. I have seen traffic signal bases modified with ramps before.

(see attached picture -

http://files.engineering.com/getfil...6ec-43b1-a406-38b097dbd0c3&file=IMG_0518.jpg)

I need a construction note telling the contractor how to do it. My guess that they would sawcut and remove the existing sidewalk (can they sawcut up against the traffic signal base plate?) and then fill in the void with some sort of mortar. Does this sound right?

 

[ACtrafficengr]

It looks to me like you could remove the sidewalk slabs along the joint lines without much sawing at all.

What does the pole foundation look like under the base plate? Is it the same size as the plate, or does it get bigger under the sidewalk?

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

[Ron]

raydefan....Agree with ACtrafficengr. One other consideration is that the primary test for "retrofit" on ADA is whether it is "readily achievable" or not. In cases where it is not, you do the best you can with the geometry.

There's a good chance that the curb around the grassy area is an easement encroachment. Check and see if you can get additional width there.

 

[ACtrafficengr]

Looking again, I'd say the driveway in the background is farther out of compliance than your corner curb ramp! What would you say the sidewalk cross slope is on that puppy? 10%?

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

[raydefan]

I think I confused you guys a little. The picture is not my project. It is a retrofitted ramp that I saw it near my house similar to what I need to do on my project. The ramp in the picture was added to put in a driveway, but the traffic signal was protected in place except for the base which was modified as shown. I need the steps the contractor took to make the base of the traffic signal work with the ramp.

Also, the standard plan for the traffic signal shows the footing being larger than the base plate and being poured to the finished surface. We assume that this is not how the contractor built it. He probably left 4" at the top to get the sidewalk in.

 

[Drumchaser]

raydefan-


As far as making the signal base work with the ramp….as long as you place expansion material around the footing you can pour the sidewalk around it to tie it in. I would not chip on the signal foundation for sure.
I do not see a ped. Button…but these have height criteria as well (ADA)


If you are a novice to the ADA requirements... perhaps you would be better suited with some in-the-field guidance. Around my stomping grounds if you construct a retro-fit and do not have reasonable excuses as to why you cannot achieve minimum slope(s) you will be removing and replacing what you have installed. (at your expense)

Local standards (drwg.s) provide for several Types of ramps (each being suited for different intersection or side street configurations, and some are modified or it is to say they are hybrids of making the scene fit the crime.

For such a small amount of work the curb ramps can be a royal pain, especially in the retrofit perspective.

In your pic I see the detectible warning surface, and it is larger than what we require. Quite certain your spec.s are not exactly as what we use, however, I bet they are pretty close.