Two- vs three-section ramp meters

[Pink Jazz]

Note that New Mexico had a temporary ramp meter in Albuquerque from May through July of 2007 for eastbound I-40 traffic from Unser Boulevard during the reconstruction of I-40 from Coors to 98th Street.  When it was first installed it had a severe programming error, flashing the lights green, yellow, and red every 14 seconds instead of turning from red to green ad 3 second intervals.  This allowed only four cars to get through every minute.

[1995hoo]

Ramp meters are in use in Virginia on I-66 and I-395 in Arlington, Alexandria, and a very minimal number of locations in Fairfax County. They're all of the "one car per green [each lane, if there are two lanes]," "no yellow phase" variety.

I don't know whether they're used elsewhere around the state.

[Revive 755]

In Chicagoland, two-section heads are used.  Almost all of them are ground mounted, the only exception I am aware of is one with a mast arm for an entrance to the WB Kennedy (I-90/I-94).

When ramp meters have occasionally appeared on the Missouri side of the St. Louis region, a two section head was used.  For at least the one on the entrance to WB US 40 from McCausland Avenue, it was dark when inactive.

[PHLBOS]

PennDOT has two-section ramp meters installed at the end of the on ramps to I-476 south of Plymouth Meeting.

US 22 along the Lehigh Valley Expressway used to have similar 2-section signals; but were taken down sometime back (not sure when).  I know that 22 had them circa 2001-2002.

I think they were also on I-78 in the same Allentown-Bethlehem corridor. Don't remember if they too were taken down.

I traveled that stretch of I-78 in 2007 and didn't see any ramp meter signals.  Personally, I doubt that this stretch of I-78 had any ramp meter signals at all.  Unlike US 22, this stretch of I-78 is relatively new (opened circa 1989) doesn't have as many interchanges located close together; and unlike the Blue Route part of I-476 (particularly south of PA 3), I don't think this part of I-78 gets as grid-locked trafficwise.  Somebody from the Lehigh Valley can confirm/clarify/correct the above.

[doogie1303]

As far as I know, Connecticut does not use either. Kurumi knows more about all of CT, and I, Fairfield County, so he could provide more insight on the topic. We would probably use R-Y-G if we did.

Growing up in Southeastern Connecticut, I can only remember of two ramp meters which are both long gone. One was on Route 9 North and was on the on-ramp after exit 12, this on-ramp now has a stop sign. The other one which was very short lived was the on-ramp for I-95 South just before the old Baldwin Bridge. This second one was only operating for a couple of months in the early 90's to try to pace traffic coming onto 95 South. They ended up taking it out since it did not help prevent traffic jams, instead they decided to close the on-ramp at certain hours on weekends in the summer.

In both cases, the meters were of the R-G type.

[froggie]

I don't know whether they're used elsewhere around the state.

No other ramp meters in Virginia besides those few along 66 and 395.  There used to be a mainline ramp meter decades ago on I-64 at the HRBT, but it's long gone.

[Darkchylde]

The ones in the Kansas City area are 2-head (R/G), and go dark when not in use.

[blanketcomputer]

As for style, overhead ramp meter signals are not common here in the Phoenix area; I have only seen them in a few places.  Most two lane ramps use pedestal-mounted meters on both sides, with the lower signals being angled towards the lane.  12 inch heads are used for the upper signals and 8 inch heads are used for the lower signals.

New overhead ramp meter signals were installed this weekend along Loop 202 West at Country Club, Alma School, and Dobson as part of the widening project. Not sure if these signals mean ADOT will be using more overhead meters in the future.

[Pink Jazz]

New overhead ramp meter signals were installed this weekend along Loop 202 West at Country Club, Alma School, and Dobson as part of the widening project. Not sure if these signals mean ADOT will be using more overhead meters in the future.

These are on the Red Mountain Freeway, right?  I wonder what will be installed on the SanTan Freeway in the future.  So far only Dobson has gotten the meters on the SanTan Freeway, and they are ground mounted and not yet activated.  I know there are plans to install meters as well as overhead DMS along the SanTan Freeway from I-10 to Val Vista through 2016.

[blanketcomputer]

These are on the Red Mountain Freeway, right?  I wonder what will be installed on the SanTan Freeway in the future.  So far only Dobson has gotten the meters on the SanTan Freeway, and they are ground mounted and not yet activated.  I know there are plans to install meters as well as overhead DMS along the SanTan Freeway from I-10 to Val Vista through 2016.

Correct, they are on the Red Mountain Freeway. These three westbound overhead meters are the first to be installed on Loop 202 Red Mountain east of Loop 101. I've noticed new loop detectors on entrance ramps in both directions along the entire widening project from Loop 101 to Broadway, so I guess we will see soon if more of these overhead meters will be installed. I personally prefer side mounted meter signals and would rather see those installed.

[peterj920]

I do find it strange in Minnesota that the ramp meters flash yellow when not actively metered.  Everywhere else they're green unless turned off when not metering.  Minnesota actually did a study with ramp meters by turning them off for 5 weeks in 2001.  Travel times increased by 22% and crashes increased by 26%.  After the study, MNDOT committed to using the meters and calibrating them based on traffic volume and to make sure the traffic stopped does not back up onto city streets.  The study can be viewed here:

http://www.dot.state.mn.us/rampmeter/study.html

[Rothman]

I do find it strange in Minnesota that the ramp meters flash yellow when not actively metered.  Everywhere else they're green unless turned off when not metering.  Minnesota actually did a study with ramp meters by turning them off for 5 weeks in 2001.  Travel times increased by 22% and crashes increased by 26%.  After the study, MNDOT committed to using the meters and calibrating them based on traffic volume and to make sure the traffic stopped does not back up onto city streets.  The study can be viewed here:

http://www.dot.state.mn.us/rampmeter/study.html

Years ago, I once interviewed with MnDOT and brought up this study, which I thought they'd appreciate.  For some reason, it seemed to be an embarrassment to them rather than a feather in their caps.

[roadfro]

I do find it strange in Minnesota that the ramp meters flash yellow when not actively metered.  Everywhere else they're green unless turned off when not metering.  Minnesota actually did a study with ramp meters by turning them off for 5 weeks in 2001.  Travel times increased by 22% and crashes increased by 26%.  After the study, MNDOT committed to using the meters and calibrating them based on traffic volume and to make sure the traffic stopped does not back up onto city streets.  The study can be viewed here:

http://www.dot.state.mn.us/rampmeter/study.html

Years ago, I once interviewed with MnDOT and brought up this study, which I thought they'd appreciate.  For some reason, it seemed to be an embarrassment to them rather than a feather in their caps.

Interesting, because I believe this study is commonly cited to demonstrate the benefits of ramp meters and/or justification for their installation.

[jakeroot]

I do find it strange in Minnesota that the ramp meters flash yellow when not actively metered.  Everywhere else they're green unless turned off when not metering.  Minnesota actually did a study with ramp meters by turning them off for 5 weeks in 2001.  Travel times increased by 22% and crashes increased by 26%.  After the study, MNDOT committed to using the meters and calibrating them based on traffic volume and to make sure the traffic stopped does not back up onto city streets.  The study can be viewed here:

http://www.dot.state.mn.us/rampmeter/study.html

Years ago, I once interviewed with MnDOT and brought up this study, which I thought they'd appreciate.  For some reason, it seemed to be an embarrassment to them rather than a feather in their caps.

Interesting, because I believe this study is commonly cited to demonstrate the benefits of ramp meters and/or justification for their installation.

Very interesting. I'm not sure how a DOT could be embarrassed by helping reduce collisions and increase traffic flow. Rothman, could you elaborate a little bit on what you mean when you say that they saw the study as an embarrassment?

[froggie]

MnDOT was embarrassed because of the politics that prompted the study, and the public backlash both before and afterwards.  Sure, they were able to statistically prove that ramp metering works, but there was a lot of public angst before the study regarding what drivers considered overly-excessive wait times to get through the meters and onto the freeway...occasionally reaching up to 15 minutes during peak traffic times.  So MnDOT was forced to revise their ramp metering algorithm to reduce those lengthy waits...and that is likely why they felt embarrassed.

The politics stems primarily from one person:  the key author of the bill that authorized the ramp meter study, State Senator Dick Day.  Day was from rural Minnesota (Owatonna area), and was mad at both ramp meters in general and that MnDOT couldn't afford to widen US 14 through his district.  It could be argued that the ramp meter study (and a follow-up HOV lane study that he wanted...he hated HOV lanes too, but FHWA regs prevented MnDOT from "shutting down" the HOV restrictions) was political payback to MnDOT for his angst.

[Rothman]

I do find it strange in Minnesota that the ramp meters flash yellow when not actively metered.  Everywhere else they're green unless turned off when not metering.  Minnesota actually did a study with ramp meters by turning them off for 5 weeks in 2001.  Travel times increased by 22% and crashes increased by 26%.  After the study, MNDOT committed to using the meters and calibrating them based on traffic volume and to make sure the traffic stopped does not back up onto city streets.  The study can be viewed here:

http://www.dot.state.mn.us/rampmeter/study.html

Years ago, I once interviewed with MnDOT and brought up this study, which I thought they'd appreciate.  For some reason, it seemed to be an embarrassment to them rather than a feather in their caps.

Interesting, because I believe this study is commonly cited to demonstrate the benefits of ramp meters and/or justification for their installation.

Very interesting. I'm not sure how a DOT could be embarrassed by helping reduce collisions and increase traffic flow. Rothman, could you elaborate a little bit on what you mean when you say that they saw the study as an embarrassment?

When I brought it up, the interviewing panel all sort of frowned and looked down and did not even ask any feeler questions to investigate my true understanding of the study.  That's what made their reaction so memorable:  Didn't even get an "Oh, you read that one, did you?" lip service kind of response.  It was really weird.

I thought I had read that there were external factors at play in the study that would cause that kind of response.  Nice of Froggie to mete them out.

[blanketcomputer]

New overhead ramp meter signals were installed this weekend along Loop 202 West at Country Club, Alma School, and Dobson as part of the widening project. Not sure if these signals mean ADOT will be using more overhead meters in the future.

These are on the Red Mountain Freeway, right?  I wonder what will be installed on the SanTan Freeway in the future.  So far only Dobson has gotten the meters on the SanTan Freeway, and they are ground mounted and not yet activated.  I know there are plans to install meters as well as overhead DMS along the SanTan Freeway from I-10 to Val Vista through 2016.

The eastbound Loop 202 Red Mountain entrance ramp at Dobson had its meter installed last weekend. It is a side-mounted meter, not overhead. I haven't been able to see the eastbound meters at Alma School or Country Club yet so I'm not sure if they are overhead or not. I'm not sure why the westbound ramps have overhead meters and eastbound has the side-mounted meters, especially when it's the same contractor doing all the FMS work.

[Buffaboy]

Not to jump completely off topic with this, is there any reason ramp meters are pretty much a non-starter in the Northeast? My travels have all been east of the Appalachians, and I've yet to actually encounter one.

Same here, I've seen them in pictures, but I have never encountered one in person, and I've traveled up (by car) and down the East Coast and into Ohio, Indiana and Illinois. I was 6 or 7 when I went to LA by air and I remember nothing.