Ramp Metering - Pros and Cons

[PHLBOS]

You also need enough of an acceleration lane to safely merge.  I think that's the reason why PennDOT disabled one of the ramp meters on I-476 (NB from US 30) because the acceleration lane is short past the meter (there is a railroad overpass shortly after the ramp).  The acceleration lane going southbound is much longer and the meter is still in use there.

Personally, I'm surprised that PennDOT even to bothered to install ramp metering at any of the non-freeway interchanges along the 6-lane portion of I-476 (US 30 & Ridge Pike interchanges) when the original reasoning to erect ramp meters was to control the traffic entry onto the undersized 4-lane section below PA 3.  A complete waste of money IMHO, especially when the system wasn't working properly in its early years of operation due to an equipment issue.

Ramp metering at the I-476/US 1 interchange IMHO are also unnecessary because the whole freeway-to-freeway interchange is already controlled with traffic signals at the mezzanine level.

I also think that is why ramp meters have never been installed on I-76, although IMHO they might help reduce some congestion, especially eastbound between I-476 and US 1.

Some of the Philly interchanges w/I-76 could use ramp metering as well; especially at some of those so-called merge or die ramps.

[froggie]

Ramp metering at the I-476/US 1 interchange IMHO are also unnecessary because the whole freeway-to-freeway interchange is already controlled with traffic signals at the mezzanine level.

However, those traffic signals don't address one of the key issues that ramp metering mitigates:  large platoons of vehicles coming down the on-ramp and merging into busy traffic at the same time.

[sipes23]

I'm not really a fan of ramp metering.  All it seems to do, at least around Chicago, is to slow the speed at which one enters the expressway.  There seems to be no difference in finding a spot on the expressway as the typical Chicago driver closes up and refuses to zipper.  I'd say about one third of those entering the expressways around here ignore the meters and just go anyway.

If they can even make it to the actual ramp meter. There have been occasions, especially on the side streets next to the Kennedy, that would be backed up for blocks because of how backed up the Kennedy was. At that point, ramp metering goes out the door and it's every man for himself

I've come to the conclusion that the purpose of metering is to ensure that the entire northwest side is a parking lot and not just the Kennedy.

[PHLBOS]

Ramp metering at the I-476/US 1 interchange IMHO are also unnecessary because the whole freeway-to-freeway interchange is already controlled with traffic signals at the mezzanine level.

However, those traffic signals don't address one of the key issues that ramp metering mitigates:  large platoons of vehicles coming down the on-ramp and merging into busy traffic at the same time.

Yes and no.  If traffic on I-476 in that area is proverbial parking lot (which it has been at times); the ramp meter signals are usually turned off.  PennDOT is on record stating that the ramp meter signals along I-476 (when they were first erected) would be turned off if the main roadway is hopelessly gridlocked as opposed to simply crowded but moving.