Traffic lights

[Bryant5493]

What intersections do you think need them? Or which intersections do you think don't warrant having one?

This one is in dire need of one, imho.

http://www.youtube.com/watch?v=tcbhzisxHd4


Be well,

Bryant

[yanksfan6129]

The intersection of River Road and Knoll Road in my town certainly could use one, but it would tie up traffic too much. It would make it too congested, which is why I think they have avoided putting one there.

[74/171FAN]

In Prince George County, VA:

VA 156 BUS/Prince George Dr at SR 646/Middle Rd
SR 630/Jefferson Park Rd at SR 646/Middle Rd
SR 630/Jefferson Park Rd at SR 1337/Crossings Blvd
VA 156 at SR 616/Laurel Spring Rd
VA 156 at SR 616/Pole Run Rd(to a lesser extent)

In Hopewell, VA:
S 6th Ave at LaPrade Ave
VA 10 at Hummel Ross Rd(there are plans to put one here)

In Petersburg, VA:
Graham Rd at ramp from I-95 South

In Colonial Heights, VA: Southpark Blvd at Southpark Cir(near VA 144)
Conduit Rd at Southpark Mall entrance
Southpark Blvd/W Roslyn Rd at ramps to/from I-95 South
Conduit Rd at E Westover Ave

[Alps]

Roundabouts work better than traffic signals up to a certain traffic volume, especially when there are a large number of conflicting vehicles (such as a large left-turn volume from one or more directions).  At certain low volumes, you can just do a two-way or even four-way stop (or blinking light), which is cheaper and easier to navigate than a roundabout.  At a certain range of high volumes, roundabout vs. traffic signal comes down to the actual expected traffic patterns and requires a traffic analysis.

[ComputerGuy]

SR 531:

25th Avenue
45 Road
E. Lake Goodwin Road/Lakewood Road

[mightyace]

SR 531:

25th Avenue
45 Road
E. Lake Goodwin Road/Lakewood Road

Huh?

[ComputerGuy]

I was talking about the intersections on WA-531 that need traffic lights.

[Bryant5493]

IMO, quite a few intersections which people think need traffic signals would work better with roundabouts instead...

I agree, but GDOT isn't currently doing multi-lane roundabouts.

Roundabouts work better than traffic signals up to a certain traffic volume, especially when there are a large number of conflicting vehicles (such as a large left-turn volume from one or more directions).  At certain low volumes, you can just do a two-way or even four-way stop (or blinking light), which is cheaper and easier to navigate than a roundabout.  At a certain range of high volumes, roundabout vs. traffic signal comes down to the actual expected traffic patterns and requires a traffic analysis.

Yeah, I contacted GDOT about a roundabout at Old National Highway (SR 279) and I-85/285, and they stated as much -- traffic lights can handle more traffic in certain situations, where roundabouts would breakdown, etc., etc.


Be well,

Bryant

[froggie]

Traffic lights can "handle more volume" if you have the lanes to handle the movements.  At which point you probably have exceeded the amount of right-of-way a roundabout would require.  Though in the case of a 6-lane road, a traffic signal is pretty much your only option anyway (though I have yet to see an upper ceiling for the capacity of a multi-lane roundabout, I can't imagine them operating well with more than 2 lanes).

[Chris]

Roundabouts only really work one two-lane highways, and sometimes on 4-lane highways, but not on 6-lane highways unless you want the craze of the Arc de Triomphe in Paris.

What I really do hate about roundabouts that they build it a lot on formerly uncontrolled intersections, so all traffic has to slow down, instead of only the minor street that intersects.

[Michael]

Bryant, how heavy is traffic on the side road you came off of?

P.S.: I think some intersections already with traffic lights need to be retimed.

P.P.S.: Where's I.C. in this thread?!

[Bryant5493]

Bryant, how heavy is traffic on the side road you came off of?

I don't have exact numbers, but there is a lot of traffic that turns left and right onto the minor road (Old Bill Cook Road) from SR 279 (Old National Highway). There are two banks (Wachovia and Bank of America), a day care, a shopping plaza (Old National Village), a fast food restaurant (Checkers), and a school (Heritage E.S.) that use this road as one of their access points. During the day, there's a pretty good deal of traffic. At night, the traffic decreases, but there is still a fair amount of traffic.

There is another signal (Godby Road) about a 1/4 mile (?) north of this intersection, so it may cause a little bit of a jam; however, safety would be improved.

I went to a meeting at a local community center where some engineers were talking about ATMs, placing advance street name signage, illuminated traffic light-mounted street name signage and pedestrian crossing signals like were placed on Buford Highway (US 23/SR 13). So, maybe this intersection improvement will be included in their plan.


Be well,

Bryant

[Chris]

click here for GDOT's traffic counts, note that all roads are represented as State Routes, also U.S. Highways and Interstate Highways.

[Bryant5493]

I posted this video on YouTube last year and sent it to GDOT. An engineer called me, we talked, and he had the timing modified. The light on the minor streets (Convention Center Concourse/Conley Street) is still long, but isn't as long.

http://www.youtube.com/watch?v=sCpY9zFRfEE


Be well,

Bryant

[Revive 755]

I have to wonder if roundabouts are inferior to traffic signals in areas with heavy platooning, and if another coordinated traffic signal would work better.  There are a few where you have to wait long enough for a gap that sometimes it seems a signal would be just as fast.  Best example of this would be 40th Street at Sheridan Boulevard in Lincoln, Nebraska -which Google shows having a signal instead of the current roundabout - though that one would work better if people would signal when exiting

[Chris]

I used to live in a new suburban development, and the arterials were lined with single lane roundabouts, and they became jammed every rushhour, single lane roundabouts do not really work with traffic volumes over 10,000 - 15,000... (and they're still advertising that they work up to 20,000 AADT)

[roadfro]

Roundabouts only really work one two-lane highways, and sometimes on 4-lane highways, but not on 6-lane highways unless you want the craze of the Arc de Triomphe in Paris

I would disagree with this statement.  The intersection of Town Center Dr and Hualapai Way (both 6-lane arterials) in the Summerlin area of Las Vegas, NV works surprisingly well.  The trick, though, is that the right hand lane for each entry is a separated right turn only lane.

[BigMattFromTexas]

San Angelo, Tx: Grape Creek Rd - N Chadbourne St
it's close to the San Angelo Colesium which gets busy during San Angelo Stampede Football season, Rodeo/Carnival, Lake View Basketball/Softball season, ect

[Duke87]

Some lights should probably just revert to flashing at hours where traffic drops. Stamford, CT put a signal in a few years back at the entrance to a middle school and a library. But it still functions as a light even on Sunday, when there's no one in school and the library's closed.

And there are a couple of lights to office parks which stay blinking on Saturday and Sunday, so I know the city is capable of timing it to do that on the weekend.

Most of the lights in town do cut off to flashing from either 11 PM or midnight to 5 AM, though, so they're sane there.

[mightyace]

Around here, many of the traffic lights in Nashville itself go to flasher after 11pm or midnight.  But, I can't recall any outside the city in suburban and rural areas working that way.

Go figure. 

[deathtopumpkins]

I wish they'd install one at my high school's entrance... 1500 kids and several hundred staff members. I can get home faster on the bus than driving it takes so long to get out of the parking lot.

[74/171FAN]

I wish they'd install one at my high school's entrance... 1500 kids and several hundred staff members. I can get home faster on the bus than driving it takes so long to get out of the parking lot.

Mine is only sightly less at about 1200 students and it takes 15 minutes for the parking lot to even be clear(and the congestion on SR 616/Laurel Spring Rd at VA 106 lasts even longer).  My planned signals on VA 156 at SR 616 West/Laurel Spring Rd and at SR 616 East/Pole Run Rd are supposed to help to an extent(along with widening of VA 156 and SR 616/Laurel Spring Rd and the addition of left-turn lanes).

[Michael]

At my college, there is a traffic light that does more harm than good.  It turns red for me, even when there are no cars coming!  I don't think it has an underground sensor loop, though.  I could go on and on about badly timed signals.

[deathtopumpkins]

Well the problem is that my school's just down Woodland Rd. from Fox Hill Rd. (VA-169), and there's 4 lanes which are pretty busy during rush hour but dead otherwise (its the main feeder route into the HRBT from my area), and there are 3 entrances, 3 exits mornings, and 2 entrances, 4 exits afternoons, but not even a shared left turn lane on Woodland. It's just terrible...
http://maps.google.com/?ie=UTF8&ll=37.056179,-76.317848&spn=0.00613,0.009656&t=h&z=17

[Alex]

Gluttening the country with too many traffic lights creates more red light running issues. The more lights you have, the more frustrated drivers get.

My local stretch of road gained three signals in the last 6 months. All of them serve neighborhood access roads and are not sequenced with one another. This creates frustration when traveling the mainline. This road is too wide for a roundabout, but I think using more u-turn lanes the way North Carolina does on U.S. 1 south of Cameron and U.S. 17 in Brunswick County may be a better way of handling some of these movements over installing a conventional traffic light.