Do you merge sooner, or later?

[RandyT]

The zipper merge works theoretically on paper, if everyone is travelling the same speed but as we all know that doesn't happen. On an Interstate, where the speed limit is 70, you'll have people driving 65, 75, 80, 90, and the Ohio State Patrol posts pictures on average of 3 times a week of a few cars they caught running over 100 mph. Tuesday, they posted a picture of one the caught running 107 mph on I-71.

Several years ago I took an 18 year old army buddy home from Ft Sill to his family home in Nebraska. Was out one night at a party while staying with his parents and was talking to one of his high school friends that was 16 at that time. She was complaining that her dad had sold her car. I asked her why her dad had sold her car and she said that she was late getting home and was going to miss her curfew and her dad clocked her at 102. He was a Nebraska Highway Patrol.

 

[MAX-24-Dean]

Death and injuries to workers.

Construction zones that have used intentional rolling slow downs before a merge is required, have had less loss of lives to construction workers. So the new "use both lanes to merge point" would be my choice. Some contracts are being written this way now.
The thought is if you can keep more traffic in all lanes prior to the merge then everyone has to slow down becasue it creates a bottle neck during peak traffic, slowing everyone. Slower traffic is always safer for workers.
The merge to left sometimes clears the right lane and encourages selfish people to try to get ahead and some try to pass as much traffic as possible by speeding up.

Used to Project Manage roadway utlity projects and traffic signals and with the merge ahead signs we had more near misses and accidents.

If you haven't noticed, we are a lawless society. Not all, but in general some people are more selfish than others and this is when the problems start.

I had to go home once minus a carpool co-worker and tell his wife and then later his kids that there dad was not coming home. He died when a speeder in the right lane (passing traffic in the left lane) lost control of thier vehicle.
The "fines double in construction zones", do not work unless there are officers present wrtting tickets all day and everyday.

 

[Hay Dude]

The zipper works because it minimizes the length of the slowdown. It blocks less intersections and reduces the gaps due to stop and go. If everyone would do it potential road rage would be reduced.

especially if everyone also listens to Kenny G while they are merging.
That also reduces road rage

haha

 

[MossRoad]

If you do anything other than what this sign says, you're the problem.

 

[oosik]

Around here I've never seen that second sign about using both lanes. No matter how it's done - there is always that idiot - racing forward in the right lane. Trying to get ahead of everybody. Jams everything up and slows everything down.

 

[WinterDeere]

The zipper merge works theoretically on paper, if everyone is travelling the same speed but as we all know that doesn't happen.

If the road is operating near capacity upstream of the merge, there will always be a slow-down at the merge, as folks adjust to maintain safe travel distance. Whether you use the 1 car length per 10 mph rule or 5 second rule, or just blindly follow your gut, the distance between you and the car in front of you is somewhat dictated by travel speed.

If you're dropping from 2 lanes to 1, and everyone is doing 60 mph with 6 car length spacing (their own vehicle being the 7th), merging all of that into one lane decreases spacing between vehicles to 2.5 car lengths. Natural tendency will be for those drivers to drop their speed closer to 25 mph, adjusting to this closer spacing.

The zipper merge works great without changing speed, when the roadway is not already operating near capacity, and can handle the higher density created by losing a lane. It also works better than everyone stopping, in the above example of full capacity, but does require speed adjustment.


Looking at roads with some nasty merges, those who remember the older Rt. 309 Expressway into Philly have some stories to tell. When I was back in college and driving that road most days, it supposedly earned top ranking as the most dangerous or deadly road in the USA, although I have no idea how they actually measured that. No on-ramps, and a very busy road with traffic typically moving above 70 mph during rush hour, where you'd have constantly cars pulling into that mess from a dead stop. And getting back to the OP, they put this road under construction for most of the early 2000's, to try to fix some of these issues. So, in addition to the original problem, they filled that F'ing mess of a road with a half dozen temporary construction lane mergers over the course of ten miles. It's a miracle there weren't mass-casualties.

The one most people talk about, as at least having the appearance of a "very scary road", is the infamous Schuylkill Expressway. Pronounced "skew-kull", it has the nickname Shurekill Deathway. There are a lot of smaller accidents on that road everyday, mostly rear-endings due to the way traffic cycles from 0 to 60 mph and then slams back to 0 mph every tenth of a mile, but I honestly don't think it's particularly deadly. It's bark is worse than its bite, I think. It sure does seem to excite some visitors though, they talk about their travels on that road like they've just done the donner pass on foot in February.

 

[newkiotiguy]

If you do anything other than what this sign says, you're the problem.

View attachment 1930070

How people can't understand this is truly unreal. It's the damn law here and people still think they know better and try to block the lane. I don't take that well

 

[Oaktree]

How people can't understand this is truly unreal. It's the damn law here and people still think they know better and try to block the lane. I don't take that well

Whoa dude, chill. Now I don't recall ever having seen one of these signs, and I will admit to being one of those who moves into the "open" lane first opportunity so as to not have to crowd in last minute. Assuming this is illegal in your state, how often is it enforced? If the answer is rarely or never then it pretty much ceases to be a law. It's certainly one that makes no sense to me. No one is "blocking" the lane.

To me blocking a lane is cruising in the passing lane doing the exact same speed as the travel lane, refusing to move over to let others by. Seems to be a very common practice in some states.

 

[RandyT]

To me blocking a lane is cruising in the passing lane doing the exact same speed as the travel lane, refusing to move over to let others by. Seems to be a very common practice in some states.

And is against the law in several states. And some states like IL does make an attempt to enforce the law.

 

[Runner]

I would merge left as soon as I knew I had to and could do it safely and with plenty of room. Then, I would leave plenty of space in front of me and not worry about people "cutting in". It's not like a couple more cars in front is going to cause the end of the world.

If some LEO wants to make a big deal out of that, go for it.

As I've gotten older, I realize that the goal in driving is to get there safely with as few conflicts as necessary. It's just pointless to try to "teach other drivers a lesson" by not letting them in when merging, tailgating, honking, gesturing, yelling or whatever.

It's not worth the fight.