Merging at high speeds

[mpd618]

I don't think this is so much about high speeds, when I don't think there's any difference in flow between late and early merging. At slower speeds or when capacity is more constrained, the idea is that the early merging behaviour is a big part of the bottleneck.

[panamaniac]

I don't think this is so much about high speeds, when I don't think there's any difference in flow between late and early merging. At slower speeds or when capacity is more constrained, the idea is that the early merging behaviour is a big part of the bottleneck.

Early or late merge, those tools who swing out to block the merge lane are unfit to be behind the wheel.

[DHLawrence]

Merge early. No mater what Outhit says late mergers piss everyone off.

[dunkalunk]

You shouldn't be merging late or early but as close to the middle of that lane as possible. The lane is called the acceleration lane as you are supposed to accelerate to the speed of traffic. Waiting too late to merge will cause you to lose your speed and potentially put you in a dangerous situation where you are stuck at the end of the lane and are forced to slow down general traffic flow. Merging late is selfish and stupid.

In the same way that the passing lane should not be used as a general travel lane but instead for passing (when volumes allow), the acceleration and deceleration lanes should be used for acceleration.

[mpd618]

You shouldn't be merging late or early but as close to the middle of that lane as possible. The lane is called the acceleration lane as you are supposed to accelerate to the speed of traffic.

That's not the kind or merging that's at issue. Rather, it's when a regular traffic lane (not an entry lane) disappears and traffic has to merge from two lanes into one -- especially at low speeds.

There's one location where I've commuted that had two lanes merge into one right after a signalized intersection. Most people would get out of the about-to-disappear lane before the intersection, and because of the bottleneck, some of them wouldn't make it through in a single light cycle. It's a waste of capacity since when then the light is red, the road ahead empties out.

Of course, the solution is not to have one lane be the one to disappear. You could probably substantially improve traffic flow in these kinds of bottlenecks through some kind of symmetrical merging signage that would encourage a zipper merge.

[markster]

There's one location where I've commuted that had two lanes merge into one right after a signalized intersection. Most people would get out of the about-to-disappear lane before the intersection, and because of the bottleneck, some of them wouldn't make it through in a single light cycle. It's a waste of capacity since when then the light is red, the road ahead empties out.

Examples include both Victoria St and Highland Rd just west of Fischer-Hallman. This boggles my mind every time.
Kitchener-Waterloo has the highest rate of "outrageously early lane selection" that I have ever seen. Just because eventually that's the lane you want to be in, doesn't mean you have to park yourself in that lane 5 km in advance! On the other hand, it often means there are free and clear lanes that I can use to pass all these people; though, I still feel like a jerk passing on the right.

Of course, the solution is not to have one lane be the one to disappear. You could probably substantially improve traffic flow in these kinds of bottlenecks through some kind of symmetrical merging signage that would encourage a zipper merge.

A little terrifying at first, because the dotted line just disappears, but you kinda get used to it.

[Duck]

I can understand where Outhit is coming from, because in "theory" he's right... empty pavement is wasted capacity. But human nature will never allow this to work. We're too orderly, and believe it's correct to wait patiently. Personally, I love when transport trucks block people (usually in BMW's with no turn signals) blast past everyone thinking they're better than everyone else.

Coming off Hwy 8 west (into town from 401), where it runs into King St. is a nightmare. I actually often shift my commute around it, I hate dealing with it so much. I hate hate hate that even though many people politely queue up in the right lane (since the left lane ends about 200 m after the intersection) - a bunch of jerks always coast up on the left, knowing full well that lane ends, then floor it up to 90 (toward a crosswalk, no less) before just ramming in without a turn signal as if it's everyone on the right's fault.

I cheer when I see cops perched just after the Honda dealership there, waiting to peg those people. I just wish they were there every day...

-Iain

[metropolis]

I love when transport trucks block people (usually in BMW's with no turn signals) blast past everyone thinking they're better than everyone else.
-Iain

FYI, tractor trilers don't block people in BMW's; we are too quck to be blocked in by anyone short of another BMW. If it seems we are being blocked in its because we are toying with those around us. If the blinker is no longer flashing its because those are "soft touch" meaning the car knows to blink only three times when changing lanes or exiting a roundabout and if we have not yet merged by the time those three blinks have happened what is a person to do? And we are better than everyone else...


All jokes aside I find that many merge lanes in Quebec are considerably shorter than in Ontario and in my time driving there I find that merging can more easily become a "white knuckle" experience than here and the shorter lanes are more prone to causing backups too, I find, but thats just a person observation. It would be interesting to see if there are stats on this somewhere comparing similar traffic volume highways with the two different approaches to merge lanes.

[timio]

I was in the LA area about a decade ago, and the on-ramps had traffic lights on them that allowed only a certain number of cars through per green. It was a great idea and I've been thinking it would work wonders in some merge situations around here and in the GTA.

[ViewFromThe42]

For highway, the key point of those lanes is to allow cars to get up to speed to match traffic on the highway; as soon as that speed is matched, merging should happen. For a BMW, that tends to be right at the start of the dashed line; for a tractor trailer, it tends to be right at the end, and so the longer merge lane length is intended for this accommodation, but individual cars should tend to hit the proper speed at the same location; it's definitely a car acceleration dependent issue. If a car attempts to merge going slower than highway traffic, it causes breaking, and in our tailgating highways this far too easily helps to spawn needless slowdowns that channel back for miles. If a car attempts to merge while going faster than traffic, such that he must change across multiple lanes or else rear end someone, it can cause the same cautious breaking and disruption to traffic.

[.FLH.]

I think Outhitt is a tool, so I didn't read his article...

I don't really have an outright opinion on merging, I sort of base it on my car's ability. I drive a 2006 Pontiac Wave, depending on how slow the moron infront of me is driving on the ramp I may need the whole lane to get up to speed. It is all about getting up to that safe speed. My sister lives out in Hespeler and often I merge on the 401 from Highway 24. I have to say that I have to GUN IT, to make it up to 90-100 and use the whole ramp in order to get to a safe speed.

[Duck]

The thread title is misleading.

-Iain