Roundabout Near a Fire Station 1

[TrafficDesigner]

Has anyone had any experiences with constructing a roundabout near a fire station? At first glance I don't see it being a problem but I want to check with others in the event that I am overlooking something. Currently the intersection is a "T" intersection with a single stop sign.

 

[Debaser]

Not to sound rude, but what do you think may be a problem? We've (UK) located emergency services facilities (fire, ambulance and police stations) near to roundabouts for a number of years without operational problems. Near being less than 100m or 300 feet. Unless you're expecting capacity issues or locking-up from day one there should be minimal delay experienced by fire engines.

The only issue would be one of the roundabout design enabling engines to carry out u-turns. Our minimum ICD is 28m/92ft, with the central island sized to accomodate the u-turn of a large artic', 4m/13ft.

If you are concerned about the closeness of the access to the roundabout causing vehicles exiting the roundabout to brake sharply when a fire engine exits the station then maybe some high friction surfacing, aka 'anti-skid' (calcined bauxite in epoxy resin) on each approach to the station could help?

(I am assuming there will be some warning signal, e.g. amber flashing lights, for traffic approaching the station when an engine is on call and about to exit).

http://www.standardsforhighways.co.uk/dmrb/vol6/section2/td1607.pdf

 

[TrafficDesigner]

I didn't take your questions as being rude at all. They are good questions. I don't believe there would be a problem but the governing jurisdiction has not seen this before and are hesitant to test the water. I think they concerned that the fire truck would not be able to get out.

They are considering flashing lights to warn drivers when there is a truck pulling out but again this is new to them and myself. I have not worked on one with emergency flashers yet.

They have plenty of right of way and the traffic volumes are not expected to reach a point where it ever be a two lane roundabout so the larger radius for the truck is not a problem.

Thank you for the link to the .PDF, I'm going to read through that during my lunch break.

Thanks for your help!

 

[Debaser]

"I didn't take your questions as being rude at all." -British politeness. Sometimes typed statemements gain meanings they don't have when spoken.


Anyway, we use amber flashing lights (colloquially known as wig-wags) on the approaches;

http://www.dft.gov.uk/pgr/roads/tss/workingdrawings/trafficsignalsp3000series/p3014wigwagsignal.pdf

Do you use something like a hatched area to keep an area clear of traffic? Could be worth applying that to the full width of carriageway outside the station, to back up the warning signals and give drivers a clue as to where to stop, and more importantly, where not to stop.

In any case, as long as there is enough of a forecourt in front of the station, such that approaching drivers can see engines before they get onto the carriageway, things should be OK. In this instance, the distance between the exit from the roundabout and the station would probably be the more critical dimension.

 

[ACtrafficengr]

We sometimes get questions about what to do if you're in a roundabout when an emergency vehicle comes through. For some reason, people don't realize you do the same thing as any other intersection - clear the intersection and then pull over once you're in a safe place.

"...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

 

[Debaser]

"We sometimes get questions about what to do if you're in a roundabout when an emergency vehicle comes through. For some reason, people don't realize you do the same thing as any other intersection - clear the intersection and then pull over once you're in a safe place."

I think the skill of the driver (of the emergency vehicle) comes into play here as well. Not hitting the siren when they're right on top of a 'civilian' vehicle causing that driver to panic.
Even in a congested state, emergency vehicles usually get through roundabouts without too much delay. Drivers tend to automatically revert to the original mode of operation, i.e. priority to the vehicle entering the roundabout, even if they didn't know it.
Our designs are usually such, that there is some escape room to allow for the 'Red Sea' effect, where two rows of vehicles part to allow a fire engine/ambulance through the middle.

 

[Debaser]

Can anyone point me to some 'modern' US roundabouts that I could look at in GoogleEarth and get afeel for your design methods?

Thanks in advance.

 

[ACtrafficengr]

Kittleson Engineering has a website with an inventory of US roundabouts, with coordinates for many. Unfortunately, the last time I tried to get on it, I got a virus warning.

"...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

 

[TrafficDesigner]

Here are some in Avon Colorado. I don't know who the designer or designers were on them. I only recently came across these.

http://maps.google.com/maps?f=q&sou...d=108168756489457376958.00000113741b6da68651e

Pan to the southeast and you will see 5 of them in a row.

Also these 4 in a row in Golden, Colorado on south Golden Road.

http://maps.google.com/maps?f=q&sou...52,-105.196838&spn=0.007293,0.013733&t=h&z=16

Here is an article that was written on the ones in Golden, Co. Apparently the businesses had an increase in sales after the roundabouts were installed.

http://ci.golden.co.us/files/roundaboutpaper.pdf

 

[Debaser]

It's always interesting to see the controversy and scepticism over roundabouts in the US. In the UK we wouldn't think twice about installing them, the only criteria being volume of traffic using an intersection and amount of land available to build on. To the extent that seeing a plan for a development on a greenfield site without roundabouts is bizarre.
(UK architects love the idea of having a 'stage' on which to place a sculpture or other 'gateway feature' and the centre island is just so tempting. I've even seen plans showing some sort of water feature in the centre island, though I assume these were an archy's joke to wind-up the engineers).