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Idea to keep cars moving at a stoplight

Started by hotdogPi, September 13, 2013, 08:33:19 PM

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UptownRoadGeek

Quote from: NE2 on November 04, 2013, 08:23:50 PM
What keeps you from running a red? Freemasons, I think.
...probably, combined with the fact that I don't want to die or see a camera flash in my rearview.
Lmao, I'm done.  :clap:


mrsman

Quote from: UptownRoadGeek on November 04, 2013, 06:07:23 PM
Quote from: NE2 on November 04, 2013, 03:38:15 PM
That's exactly what is done in the real world examples given. For example: http://maps.google.com/?ll=28.721416,-81.319111&spn=0.003618,0.007086&t=h&layer=c&cbll=28.721483,-81.318924&panoid=ryCbZ9DCVKPErr-TtLamXQ&cbp=12,108.6,,2,2.6&z=18

That looks like it could be extremely dangerous from an outsiders POV. As someone above stated, there's nothing keeping turning traffic out of the far right lane. Honestly, what is the point in even having the left lane there if it's not going to bypass the intersection with its counterpart. If that was where I live you would have a crapload of people changing lanes and jumping over as soon as the light hits yellow. Another thing that I found confusing, probably because of how it's done where I'm from, was having 5 signals hanging over 3 lanes on the same post.

For a long time the intersection at Cahuenga and Odin near the Hollywood Bowl had a similar configuation.  2 lanes of northbound Cahuenga were continuous, the left lane from Odin became a left lane for Cahuenga (3 lanes north of the intersection).  THe right lane from Odin became the right lane of Cahuenga.  And only southbound Cauhenga saw a stop sign.  A fast but dangerous intersection.  Fortunately, the city changed this light to a more traditional signaled intersection.

1995hoo

Quote from: 1 on September 13, 2013, 08:33:19 PM
On a road where both sides are 2 or more lanes, and there is a traffic light that is there because of only one side of the road, here is an idea:

The side that doesn't have the street or business can have the right lane continue, ignoring the traffic light. If someone on the street wants to turn left, he can go onto the left lane of the road.

Example where this could happen (with business) here. The business is on the left, so the right side would have the right lane continue freely.

I encountered two configurations like the one seen in this video last Friday on US-1 just north of central Melbourne in Florida (the one seen here is the second of the two). They seem to fit what the OP had in mind. Note the white sign on the right side of the road saying the two right lanes have a continuous green. The road runs pretty much right along the Indian River through this area, so there's not much on the right side of the road.

Click thumbnail to play video.

"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

realjd

Quote from: 1995hoo on December 05, 2013, 03:33:00 PM
Quote from: 1 on September 13, 2013, 08:33:19 PM
On a road where both sides are 2 or more lanes, and there is a traffic light that is there because of only one side of the road, here is an idea:

The side that doesn't have the street or business can have the right lane continue, ignoring the traffic light. If someone on the street wants to turn left, he can go onto the left lane of the road.

Example where this could happen (with business) here. The business is on the left, so the right side would have the right lane continue freely.

I encountered two configurations like the one seen in this video last Friday on US-1 just north of central Melbourne in Florida (the one seen here is the second of the two). They seem to fit what the OP had in mind. Note the white sign on the right side of the road saying the two right lanes have a continuous green. The road runs pretty much right along the Indian River through this area, so there's not much on the right side of the road.

Click thumbnail to play video.



The Indian River is the only reason the right lanes have a continuous green. We have a number of them here in Brevard County:
* US1 at NASA Blvd (SR518)
* US1 at Cherry Lane
* US1 at Port Malabar Blvd
* US1 at Malabar Road (SR514)
* SRA1A at Pineda Cswy (SR404)

There are a few locations that otherwise seem like great candidates for the continuous green lights but aren't configured that way due to crosswalks. US1 at Palm Bay Road comes to mind.

tradephoric

#79
Quote from: NE2 on November 04, 2013, 06:20:35 PM
Quote from: UptownRoadGeek on November 04, 2013, 06:07:23 PM
As someone above stated, there's nothing keeping turning traffic out of the far right lane.
There's a double white line with 1-2 feet between, and a dashed line to the right of the left turn movement indicating which lane you must turn into.

Here's a streetview image of a continuous green through lane (CGTL) intersection in Jacksonville, Florida.  The grey SUV could easily overlook the faded double white line and cross into the continuous green lanes.
 


Quote from: NE2 on November 04, 2013, 05:38:57 PM
I found a safety analysis: http://www.trforum.org/journal/downloads/2011v50n1_01_SafetyAnalysis.pdf
Maybe someone who cares more can extract the relevant information.

According to the study, public opposition in Jacksonville has resulted in the removal of several CGTLs as "citizens feel the intersections are not safe, especially for motorists unfamiliar with their design."   The results of the study found a "significant difference between the proportions of sideswipe crashes in the CGTL direction compared with the opposite direction."   To improve safety, the researchers suggest adding "highly visible raised separators, in lieu of double white lines and raised rounded domes [to] create a distinct separation between the continuous through traffic and the adjacent lanes" .

Adding raised separators could significantly improve safety and public perception of the design.  Here's an example of raised separators at a CGTL intersection: 
https://www.google.com/maps/@39.6470711,-79.9773931,3a,90y,102.49h,74.53t/data=!3m4!1e1!3m2!1sDDbMKPCXK3ZQnced-4PrWQ!2e0

roadfro

Quote from: tradephoric on September 28, 2014, 12:07:44 PM
Here's a streetview image of a continuous green through lane (CGTL) intersection in Jacksonville, Florida.  The grey SUV could easily overlook the faded double white line and cross into the continuous green lanes.
<snipped image>
Quote from: NE2 on November 04, 2013, 05:38:57 PM
I found a safety analysis: http://www.trforum.org/journal/downloads/2011v50n1_01_SafetyAnalysis.pdf
Maybe someone who cares more can extract the relevant information.

According to the study, public opposition in Jacksonville has resulted in the removal of several CGTLs as "citizens feel the intersections are not safe, especially for motorists unfamiliar with their design."   The results of the study found a "significant difference between the proportions of sideswipe crashes in the CGTL direction compared with the opposite direction."   To improve safety, the researchers suggest adding "highly visible raised separators, in lieu of double white lines and raised rounded domes [to] create a distinct separation between the continuous through traffic and the adjacent lanes" .

Adding raised separators could significantly improve safety and public perception of the design.  Here's an example of raised separators at a CGTL intersection: 
https://www.google.com/maps/@39.6470711,-79.9773931,3a,90y,102.49h,74.53t/data=!3m4!1e1!3m2!1sDDbMKPCXK3ZQnced-4PrWQ!2e0

I would have to agree on the public perception of the CGTL if there is not a physical barrier. From a driver expectation viewpoint, if you're unfamiliar with the intersection and coming from the side road with a green light, you will likely be confused why cars are still going through on the main road--especially if you can't see the double white lines.

Nevada has a few of these intersections (we call them "Hi-T" intersections). Where implemented, there is typically a narrow concrete median and raised delineators separating the continuous through lanes. (See my post on page 1 of this thread for examples)
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.

tradephoric

Here's a streetview image of US1 & Cherry Street near Melbourne, Florida.  It looks like a conventional T-intersection.  How are drivers on the side-street suppose to know there are continuous green lanes on the main street?   

https://www.google.com/maps/@28.099863,-80.61306,3a,75y,83.05h,81.85t/data=!3m4!1e1!3m2!1snpEm_i1XgJ0izBW98p6LzA!2e0

tradephoric

https://www.google.com/maps/@36.1959152,-115.2402639,3a,75y,65.18h,69.42t/data=!3m4!1e1!3m2!1sHD1P_wnMOqTYBFxlyXJbBw!2e0?hl=en

Hey roadfro.  In this example, the continuous green lanes have a standard 3-section signal head.  Do the two right most lanes rest in green unless if a pedestrian actuates the pusbhutton? 

The Nevada examples, that include a physical barrier, look a lot safer than the Florida examples with no barrier.


roadfro

Quote from: tradephoric on September 30, 2014, 01:46:05 PM
https://www.google.com/maps/@36.1959152,-115.2402639,3a,75y,65.18h,69.42t/data=!3m4!1e1!3m2!1sHD1P_wnMOqTYBFxlyXJbBw!2e0?hl=en

Hey roadfro.  In this example, the continuous green lanes have a standard 3-section signal head.  Do the two right most lanes rest in green unless if a pedestrian actuates the pusbhutton? 

The Nevada examples, that include a physical barrier, look a lot safer than the Florida examples with no barrier.

Although that example is near the house I grew up in, I've never seen a pedestrian cross there. I would make the assumption that the right two lanes do rest in green unless a pedestrian presses the button.
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.

jakeroot

This is a continuous green-t (i.e. seagull intersection) near where I grew up in South Hill, Washington (near Puyallup, south of Seattle). There's a POI directly after the traffic merges into the mainline so lots of people have to rush over to the right immediately. I suppose the intersection seems then, poorly designed. But I can assure you, it flows very well (all things considered).

(pardon my unnecessary expletives)




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