I’m surprised that it doesn’t happen more often.
This morning we were merging onto Northbound I-5 from Eastbound SR-16 and got hit from behind. That location is another fine example of bad freeway design mixed with drivers who can’t merge.
Two lanes end as traffic merges onto I-5. The engineers gave traffic plenty of time to perform this merge by extended the length of the ending lanes for half a mile or so. Unfortunately they didn’t seem to consider the mentality of the standard Washington State motorist. Instead of attempting to perform the merge … oh wait, let me define merge again.
(Wes put’s on his comically exaggerated hat and smile reminiscent of those employed by kiddie show hosts since the 1950’s)
Hiya Kids! Say Hiya Mr. Merger! (Wes waits, plastic smile still gleaming). Ok, can you count to 2?!? Sure you can! Say it with me, 1 and 2 and 1 and 2 and 1 and 2! Yay!. Now we’re merging. Today, were going to learn a new word that helps us merge on the freeway, ok!?! Yay! Here it is, Ayegoyougo. It’s pronounced like this ‘I-go-you-go’. Say it with me ….
/sarcasm_off
Where was I? Oh yah, so, the folks who designed this traffic blending forgot that drivers here don’t know hot to merge. When seeing that they lane they are in is about to end, the intended behavior is that driver’s should look for the earliest safe place to insert themselves into a lane that won’t be ending, or simply put, safely merge to the left. To be honest, about half the drivers actually do this. The problem is the remainder see their lane ending, see the slowing (stopped really) traffic in the lane to the left, look ahead at half a wide open mile in front of them and gun it.
The net effect of the behavior is that they and up causing a hideous backup right where the lane ends as they jam their car to the left (or worse drive on the shoulder a bit farther to get an extra couple car lengths ahead). This backup blocks traffic all the way to (sometimes before the beginning of the merge) and builds into the traffic equivalent of something you’d call the plumber for.
That’s where we found ourselves this morning. I merged into the left lane at a safe location and sat in the gagged up mess that is there almost every day. Unfortunately behind us was a driver that wasn’t paying attention to the traffic ahead, braked too late and slid into our rear bumper.
Here’s the good news, so far it doesn’t look like there was any damage to either car. Josh, the driver of the other car, was apologetic and relieved as we examined our bumpers. It was an accident, and those things happen. We exchanged information just in case we missed some damage. We thanked God for well designed cars, shook hands and went on our way.
Here’s the long and short of it, my wife is 6 months pregnant. Every day we fight this merge and several others just like it. Every day these same people put our health and property at risk so they can get another half a mile ahead. Fine, they don’t respect us. They don’t care about our property or safety. I get that. We live in a society where we are taught to place personal desire above all of our competitors. I get that too, I don’t buy it, but I understand it. It’s not just presented as acceptable behavior but engrained as a right that each individual is entitled to.
I just wish there was a way to make my unborn son exempt from it for a while. Just some time to get him going before this avalanche of selfishness tries to plow him under. It makes me almost want to put that “baby on board” sign up in the car. Of course that just makes me think of the number of times I’ve seen them in the back window of the car that just cut me off.
Oh, and the icing on the cake. As we tried to work our way to the shoulder after the accident, we got a series of annoyed angry honks from the same drivers that cause the mess as they rocketed up the closing lane. Lovely.
Don’t drive angry, drive weird!
A Plague of Buses 
First, sorry about the accident. Especially the whole “accident with a pregnant wife in the car” thing. Never fun.
But, one little quibble: Why wouldn’t one drive all the way to the end of the merge lane and then merge nicely there? If everybody merged 1/2-mile before the end of said merge lane, doesn’t that waste a good 1/2-mile of freeway, and push all that traffic into a single lane, thus pushing the backup further? It seems the problem isn’t people zooming up to the end and then forcing their way in, it’s people who merge too soon. Or to put it a different way, you don’t try to force the zipper to zip 1/2 way up, you start at the bottom.
Of course, I’m only talking of situations where two lanes merge into one, not where the two lanes go different places, like the I-5/16/Tacoma Mall interchange going the other way. But in places like you’re describing, or the Purdy exit between 3-7 p.m., it makes more sense for both lanes to be full right up to the end, and then cars merge in an orderly fashion, rather than randomly merging anywhere along the way.
My 2 cents, anyway.
By: Dan on October 26, 2010
at 2:31 pm
Well if that was the intent we would design our merges as a single car length entrance to the freeway. The zipper is designed to close the whole length of your coat not just the bit at the bottom.
The goal is to be able to merge without coming to a complete stop.
The zipper is designed with an empty space on each side allowing the sides to fit together. If zippers worked the way you suggest they would never close. It would just bind up at one end.
By: Wes on October 26, 2010
at 4:23 pm
If my first reply doesn’t help illustrate my point here’s another.
Traffic is fluid dynamics. When people wait until the last minute the effect on traffic flow is that of an injection not a merge. As volume increases the injection site becomes overloaded.
By: Wes on October 26, 2010
at 5:20 pm
I think the problem is that, with either theory, there is a presupposition of X amount of space per car, in order to keep traffic flowing smoothly. But when you suddenly cram more cars into the equation, cars can’t keep flowing smoothly no matter the merge pattern.
By: DanW on October 26, 2010
at 8:32 pm
Well, when you look at where the backup dissolves you see where the backup started. Since in this case and every case I mention the backup dissolves shortly after the end of the merging lanes it’s safe to say that the blockage was in that location. If the blockage were occurring at the beginning of the merge the backup would be further back. Again the problem is that people rush to the front and attempt to inject themselves into the flow, more flow in one location equals blockage.
The design of this style of merge was to spread the additional flow all along that half mile. Again, fluid dynamics. It’s the equivalent of using a larger pipe. When people rush to the front they artificially restrict the flow from what was half a mile down to nearly zero so that the merging driver must force his way in to the lane, stop or drive on the shoulder.
There isn’t a presupposition of X amount of space per car to keep traffic flowing, it’s a studied fact. Traffic flow isn’t analogous to fluid dynamics, it is fluid dynamics. Here’s a link to software that applies fluid dynamic algorithms to traffic http://ercim-news.ercim.eu/fluid-dynamic-approach-to-traffic-flow-problems . If you are a math nerd, here’s that http://www.physics.udel.edu/~jim/Advection/TraffficFlow.htm . They are able to calculate using these equations that every 1 minute of blockage results in 5 minutes of delay.
So, I think giving more room to merge is a nice feature and good design until you fail to factor in the folks who see that extra piece of roadway and rather than looking at it as roomy safe opportunity afforded them to merge into the flow, they rush up trying to get ahead of a half mile of cars.
People don’t need to know all this to do the right thing here; they simple need to follow the rule. Here it is from the Washington State Drivers Guide.
Here it is from the Washington State Drivers Guide.
Space to Merge: Anytime you want to merge with other traffic, you need a gap of about four seconds. If you move into the middle of a four-second gap, both you and the vehicle behind you have a two-second following distance. You need a four-second gap whenever you change lanes, enter a roadway, or when your lane merges with another travel lane.
• Do not try to merge into a gap that is too small. A small gap can quickly become even smaller. Enter a gap that gives you enough space cushions to be safe.
If they rush up to the front where the blockages is they have no hope of merging according to the instruction above.
By: Wes on October 26, 2010
at 10:49 pm
Glad you and Tammy are okay. I got in an accident when I was pregnant once. Got a concussion and very banged up hand from it jamming into the steering wheel, but baby was fine. Although now that he’s 18 I wonder…Just kidding. I love my boy. Take care and tell Tammy hi for me.
By: Lori on November 6, 2010
at 9:40 pm