Congestion caused by driver confusion/lack of awareness

[webny99]

Before I dive into the weeds with a case study, the purpose of this thread is twofold: firstly to discuss congestion issues caused by drivers lacking intuition and/or awareness, and secondly to discuss what measures state DOT's do/don't and should/shouldn't be taking to mitigate these issues during road work and other construction projects.



Now for case study #1 which was the inspiration for this thread. There is a recently started bridge rehabilitation project on the Alexander St overpass of I-490 (NY) that has resulted in long-term left-lane closures on both directions of I-490. It's primarily a six-lane freeway in this area; however there are auxiliary lanes between interchanges, including through the project area, which is between Exits 16 and 17. So there are typically eight lanes here but that's been reduced to six with the left lane closures.

In theory, that should be pretty manageable - you're essentially just turning the auxiliary lane into a general purpose lane for the duration of the project, and as long as drivers are made aware of this and can make informed lane choices accordingly, traffic flow should be maintained through the work zone with only minor slowdowns.

In practice, lack of awareness of the westbound lane configuration has turned it into one of the most colossal traffic management failures in recent history.

To give the positive side of things first, eastbound traffic flow through the work zone has been pretty good. Importantly, the left hand entrance ramp to I-490 EB from NY 15 is also closed as part of the project. That ramp contributes a thru lane to I-490 EB, so with it being closed the existing left lane on I-490 remains the left lane going through the work zone, instead of becoming the center lane. Meanwhile, the far right lane on I-490, which becomes an exit only lane for Exit 17, now functions as a thru lane through the work zone, and traffic has about 1/4 mile to shift to the left once past the work zone. There's been a few minor slowdowns at rush hour, but overall it's been pretty smooth.

Westbound is a whole different story, largely thanks to the inexplicable lane configuration (which predates this construction project) of only two thru lanes on I-490 for about 500 feet before a new right lane opens just past Exit 16. This isn't normally a big problem unless there's an incident downstream, but add in the left lane closure, and that would mean there's only one thru lane for I-490 approaching Exit 16, which is a massive problem. To NYSDOT's credit, they identified this issue and have restriped/realigned the lanes so that the center and right lanes shift left exiting the work zone, so that they can both function as thru lanes for I-490 traffic. They also patched over the leftmost arrow on this sign to indicate that the lane does not presently exit to Clinton Ave and can be used as a thru lane.

This attempt at maintaining traffic flow turned out to be futile, however, as drivers have almost exclusively failed to pick up on the new configuration. Instead of shifting one lane to the right in response to the lane realignment, everyone stays in the center lane, which quickly becomes overwhelmed. Then when congestion inevitably develops approaching the lane closure, the center and left lanes slow to a crawl up to the merge, while the right lane remains completely free flowing. Even despite this, and despite the right lane being completely viable as a thru lane through the work zone, drivers continue to queue in the left and center lanes while the right lane remains largely empty beyond Exit 18.

Now after about a week with this configuration, the backups have been persistent through morning rush hour, starting again as early as 1PM, and slowing traffic to a crawl for almost 2 miles during afternoon rush hour. Things reached a new low today, when an apparent accident near the work zone further thwarted any semblance of normal traffic flow. It got so bad that mainline traffic backed up beyond Winton Rd (Exit 20), and the exit ramps for both Culver and Monroe Ave backed right up onto the mainline. At that point, anyone with a destination outside of Downtown or the South Wedge would have been better off taking I-590 to I-390 or using some combination of surface streets to reach their destination.

I commend NYSDOT for at least trying to preempt this issue with the lane realignment, but driver stupidity (for lack of a better term) has prevailed... and with school starting in a couple of weeks, things are bound to get a whole lot worse before the construction wraps up unless NYSDOT takes some additional measures to encourage drivers to make use of the realigned lanes.

Thoughts on what NYSDOT should do here, commentary on this issue or similar issues you've encountered, and any other topical thoughts are appreciated!

[vdeane]

I was thinking about this thread as I was driving home today.  I feel like the usual Northway delays would be a lot less if drivers weren't making them worse.  Even now, close to five years after the exit 4 project finished, people still insist on merging as early as possible, often before the striping separating the ramp from the travel lanes even ends, and people in the right lane instead on trying to force their way into the middle lane instead of simply working to make the merge of traffic entering as smooth as possible given the traffic levels.  The combination of the two causes traffic to grind to a halt.  The aux lane, meanwhile, goes largely unused; it's basically an express lane for traffic getting off at exit 5.

[jeffandnicole]

I was thinking about this thread as I was driving home today.  I feel like the usual Northway delays would be a lot less if drivers weren't making them worse.  Even now, close to five years after the exit 4 project finished, people still insist on merging as early as possible, often before the striping separating the ramp from the travel lanes even ends, and people in the right lane instead on trying to force their way into the middle lane instead of simply working to make the merge of traffic entering as smooth as possible given the traffic levels.  The combination of the two causes traffic to grind to a halt.  The aux lane, meanwhile, goes largely unused; it's basically an express lane for traffic getting off at exit 5.

There's something extremely relatable to this:  The argument with zipper merging.  Some people want to merge as early as possible, no matter how much it's encouraged to keep going.  Same thing here:  People run over paint.  People don't speed up and merge into traffic.  Nothing short of a physical barrier will prevent this issue from occurring.

[Max Rockatansky]

Ran into the zipper merge issue on southbound CA 41 a couple weeks ago approaching Hanford-Armona Road.  A construction crew was working on the traffic sensors in the right lane and had it closed.  All the traffic had gotten over so early that there was a half mile backup before the zipper merge ended.  I just stuck to the lane that ended and blew past almost everyone

[Road Hog]

Hats off to ARDOT for finally recognizing the spaghetti effect in that short 2-mile segment of I-40 between I-30 and US 67 (future I-57).

As part of the I-30 Connector project, they reconfigured the I-30 interchange early on to merge onto I-40 on the inside lanes so the northbound traffic could exit left at the existing 67 triangle downstream. That was the simple solution. Young me was wanting a right-exit flyover at the 67 Y.

[webny99]

I was thinking about this thread as I was driving home today.  I feel like the usual Northway delays would be a lot less if drivers weren't making them worse.  Even now, close to five years after the exit 4 project finished, people still insist on merging as early as possible, often before the striping separating the ramp from the travel lanes even ends, and people in the right lane instead on trying to force their way into the middle lane instead of simply working to make the merge of traffic entering as smooth as possible given the traffic levels.  The combination of the two causes traffic to grind to a halt.  The aux lane, meanwhile, goes largely unused; it's basically an express lane for traffic getting off at exit 5.

This also applies to this stretch of I-490 westbound during normal conditions. The lack of an option lane connecting to the thru lane beyond Exit 16 means that everyone merges out of the right lane as early as Exit 18 so the center and left lanes move at or below speed while the right lane (and beyond Exit 17, also the auxiliary lane) remain largely empty. This issue becomes progressively worse throughout the day as the percentage of traffic exiting to Downtown declines, to the point where you might even mistake the westbound rush hour for being in the afternoon instead of the morning - when in reality, the problem is 90% of the traffic using 50% of the lanes in the afternoon while being much more evenly split in the morning.

[webny99]

Now for case study #1 which was the inspiration for this thread. There is a recently started bridge rehabilitation project on the Alexander St overpass of I-490 (NY) that has resulted in long-term left-lane closures on both directions of I-490. It's primarily a six-lane freeway in this area; however there are auxiliary lanes between interchanges, including through the project area, which is between Exits 16 and 17. So there are typically eight lanes here but that's been reduced to six with the left lane closures.

In theory, that should be pretty manageable - you're essentially just turning the auxiliary lane into a general purpose lane for the duration of the project, and as long as drivers are made aware of this and can make informed lane choices accordingly, traffic flow should be maintained through the work zone with only minor slowdowns.

In practice, lack of awareness of the westbound lane configuration has turned it into one of the most colossal traffic management failures in recent history.

Literally the day after I posted this massive rant, drivers seemingly started to figure out the new traffic pattern, and in less than 48 hours the congestion issues went from extraordinary to really pretty minimal. 

[jeffandnicole]

Now for case study #1 which was the inspiration for this thread. There is a recently started bridge rehabilitation project on the Alexander St overpass of I-490 (NY) that has resulted in long-term left-lane closures on both directions of I-490. It's primarily a six-lane freeway in this area; however there are auxiliary lanes between interchanges, including through the project area, which is between Exits 16 and 17. So there are typically eight lanes here but that's been reduced to six with the left lane closures.

In theory, that should be pretty manageable - you're essentially just turning the auxiliary lane into a general purpose lane for the duration of the project, and as long as drivers are made aware of this and can make informed lane choices accordingly, traffic flow should be maintained through the work zone with only minor slowdowns.

In practice, lack of awareness of the westbound lane configuration has turned it into one of the most colossal traffic management failures in recent history.

Literally the day after I posted this massive rant, drivers seemingly started to figure out the new traffic pattern, and in less than 48 hours the congestion issues went from extraordinary to really pretty minimal. 

So while you looked at it as a case study and a traffic management failure, traffic engineers and construction project managers would look at this as: Normal.

It's been long noted at projects almost anywhere that motorists are creatures of habit.  No matter how many signs, news stories and social media announcements are posted, some people aren't going to pay attention.  And even if that "some" is a small percentage, it will lead to congestion. 

After a period of time, traffic starts getting better.  People learn the new traffic pattern.  Some will find another way to travel to avoid the congestion. Some will start earlier or later to avoid peak periods. 

When they start work in the summer, there's some benefits...traffic volumes are often lower because people are on vacation, and the jams aren't as long distance-wise.  But there's a negative...because people are away, they may have been away for the first week of the project. When they return, they are now seeing the new traffic pattern for the first time, and now there's another week of people adjusting to the new traffic pattern.  But people get used to it...as you noted.

This is hardly a phenomenon that occurred with this project. You didn't indicate there's anything wrong with signage or such. From the sounds of it, this is what occurs at nearly every project, and it eventually works itself out.

[webny99]

Agreed, even when I made my initial post I did feel there was a degree of inevitability to things getting better with time.

However, after driving through the work zone again today, I'm going to walk back my previous post and say that the westbound configuration is still an issue. While there's nothing wrong with the signage per se, I would argue the right lane now being a thru lane is very inadequately signed considering it's always been an exit only lane. There is no indication that it can now be used for I-490 thru traffic other than the covered-over exit only arrow, which probably half of drivers or more haven't even noticed.