Traffic Management for Accidents

[vdeane]

Why don't DOTs and related agencies do any traffic management when there's an accident?  I recently had a horrendous experience crossing the Tappan Zee Bridge due to an accident taking out the right westbound lane.  It took an hour and a half of sitting though bumper to bumper traffic to travel three miles.  Additionally, the zipper lane was open for the eastbound lanes, so four lanes of traffic was essentially merging to two, and people in those two lanes were traveling slowly to gawk.  All the Thruway Authority could be bothered to do was post "expect delays" (which implies five minute delays, not hour and a half delays, and the delay was probably longer for most because I'm betting traffic was backed up all the way into Connecticut by the time I got through) on VMS signs they already had.  What they should have done is open the zipper lane for the westbound side and set up a lane shift to deal with the merging, place a fleet of police cars on the bridge to ticket gawkers, change the VMS warnings from "expect delays" to "extreme delays", and setup more VMS signs to say that gawkers will be fined for impeding traffic.  Had they done this, the backup would have been much less severe, and I'm about to send them a nasty email to that effect.  But why don't agencies do this?

[6a]

I've been seeing a lot of hot pink "accident ahead" signs lately...I think that is a Columbus PD thing though.  Usually they are used when there is a long term (hours) situation, rather than the odd fender bender.  I have seen some portable VMSes and even cones to close lanes, so I think the idea is out there if not everywhere yet.

Edit: this is it.  Apparently it is in the MUTCD...I'll be damned.

[roadfro]

Why don't DOTs and related agencies do any traffic management when there's an accident?  <snip>  But why don't agencies do this?

I imagine it's a combination of cost & manpower and also effectiveness.


On one point, the DOT or similar agency would need to know that there is a major accident that has occurred, and to know the extent of the traffic delays that are being caused. For some agencies, they have regional traffic command centers with cameras, traffic flow sensors and other ITS equipment monitored by personnel during busy times, so they would be alerted to problems fairly quickly. Other agencies may not even have centralized traffic centers at all.

With the VMS displays, that is something that could've been improved. Instead of the ambiguous "expect delays" message, more detailed information could be given upstream, such as "Accident ahead on bridge / right lane blocked / expect delays". Such a message, displayed well upstream of the accident, would give drivers sufficient notice that they might alter their route, or would at least be prepared for a major wait. Of course, this assumes there are peace officers present at the scene (or personnel monitoring ITS equipment) that can evaluate the situation and communicate it to the VMS operators to get out the relevant information to drivers.


Another thing to consider is whether any sort of traffic control would really be effective. Is it worth the cost of sending a DOT employee to go and figure out the situation to place a temporary lane merge situation up? The DOT person would likely have to sit through the accident backup just to get to the location, and then would need to figure out some way of setting up temporary traffic control devices in the middle of an incident already in progress (where by that time, usually drivers have developed their own control situation to get themselves around the situation. In many scenarios, by the time a DOT person would've made it out to the scene, set up traffic control and other incident management signs, the situation would be fairly dissolved. It may be possible that someone could have come to open the zipper lane, as you suggest, which would need coordination with other traffic concerns (i.e. someone would have to make a judgement call on whether that would've had too great a negative impact on the opposing travel lanes, and when the lane would need to be re-zippered to the previous condition).

As to the "fleet" of police and ticketing for "gawking", that's not something that most police agencies would have the manpower to do--the police's primary responsibility should be investigating the accident, collecting necessary information, and then ensuring that the involved vehicles are removed from the roadway ASAP. Besides, I'm not even sure that states have a law or regulation regarding "gawking"...

I've been seeing a lot of hot pink "accident ahead" signs lately...  <snip>  Apparently it is in the MUTCD...I'll be damned.

The 2009 MUTCD added three new sign colors, with a fluorescent pink color specifically designated for "incident management" signs. This is relatively new, so many agencies aren't using this quite yet.

Same situation applies though. Is it worth it to go set up a bunch of signs. Possibly for a situation which has a longer-term effect on a road (such as investigating a fatal accident), but not for the everyday fender bender.

[vdeane]

Well, this example was from New York.  Of course the police have enough cars to do enforcement.  I'm sure they can pull some off from speed enforcement (such as the one sitting on the other end of the bridge to catch anyone going faster than 55).  I didn't see any police on the scene but they were probably long gone by the time I got through.  I'll have a picture in a day or two once I get my New Haven meet pics uploaded to Picasa Web Albums.  I'm pretty sure impeding traffic is an offence just about anywhere (and if not, should be).  Traffic on the eastbound side was flowing at about 70 mph and wouldn't have been affected by removing the zipper lane.

I'm pretty sure the Thruway Authority knew about this.  They mandate the use of their own roadside assistance services, one of which was on site when I passed (looks like someone had a flat tire and then got rear-ended by a car or two moving at high speeds).  Even AAA just contracts out to them for Thruway accidents.

[Scott5114]

I'm pretty sure the fluorescent pink was added in the 2003 MUTCD, possibly earlier.

[Brandon]

ISTHA uses their VMSs along the tollways.  IDiOT on the other hand...well, there's always AM780.

[Sykotyk]

I've seen the 'hot pink' Accident Ahead signs in many places. All involving big accidents that will require quite a bit of cleanup or a lot of wrecker work (i.e., car mangled down a hillside, overturned tractor-trailer, spilled load, etc). It's better than what most accidents have and that's just a cop with the lights on blocking the lane you can't be in.

[vdeane]

Well, this example was from New York.  Of course the police have enough cars to do enforcement.  I'm sure they can pull some off from speed enforcement (such as the one sitting on the other end of the bridge to catch anyone going faster than 55).  I didn't see any police on the scene but they were probably long gone by the time I got through.  I'll have a picture in a day or two once I get my New Haven meet pics uploaded to Picasa Web Albums.  I'm pretty sure impeding traffic is an offence just about anywhere (and if not, should be).  Traffic on the eastbound side was flowing at about 70 mph and wouldn't have been affected by removing the zipper lane.

I'm pretty sure the Thruway Authority knew about this.  They mandate the use of their own roadside assistance services, one of which was on site when I passed (looks like someone had a flat tire and then got rear-ended by a car or two moving at high speeds).  Even AAA just contracts out to them for Thruway accidents.

Here's the picture I mentioned:


And after I passed the accident:

[BamaZeus]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

[Alps]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

I either saw that in an ASCE presentation or on TV for the $1,000,000 invention show.

[Brandon]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

Nah.  'Round here, they'd still rubberneck at the damn curtain!

[allniter89]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

Nah.  'Round here, they'd still rubberneck at the damn curtain!

I know you're right Brandon!

[Sykotyk]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

Nah.  'Round here, they'd still rubberneck at the damn curtain!

I know you're right Brandon!

Sadly, I'm sure he's right.

[Zmapper]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

Nah.  'Round here, they'd still rubberneck at the damn curtain!

I know you're right Brandon!

Sadly, I'm sure he's right.

People would just be like "ZOMG a white curtain! How pretty! Let me crawl by at 25mph to stare at all those white threads!"

[PAHighways]

I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.

I've never seen curtains being used here at non-fatal accident scenes.

[vdeane]

If anyone's curious, here's the Thruway response:

The New York State Thruway Authority makes every effort to keep motorists advised of changing road conditions and accidents.

The Tappan Zee Bridge accident and traffic congestion which resulted that you referred to in your email below
were the subject of several TRANSalerts until each was cleared. In addition, messaging was activated on the Highway Radio Advisory Network, Variable Message Service (Cross Westchester Expressway and Thruway mainline) and the Thruway Authority web site. TRANSCOM, a coalition of 16 transportation and public safety agencies in the New York, New Jersey, and Connecticut metropolitan region; and the Hudson Valley Transportation Management Center were also notified during these incidents. Messaging and notifications were timely and accurately reflected conditions.

Many travelers take advantage of the free TRANSalert service that provides real-time updates via emails and text messages. Information on how to subscribe to TRANSalert is available at the weblink http://www.thruway.ny.gov/tas/index.html .Your subscription can be tailored to specific times of the day and to specific locations.

Traffic conditions also are available by calling the toll-free number 1-800-THRUWAY (1-800-847-8929) and selecting Option 2.

Should you have further questions or comments relating to the Thruway, please do not hesitate to contact Public Information at http://www.thruway.ny.gov/about/contact.html .

[hobsini2]

Actually a slight correction to IDiOT.  They occasionally will use the big electric overhead signs to alert about congestion or lane closures in the Chicago area.

[SSOWorld]

Actually a slight correction to IDiOT.  They occasionally will use the big electric overhead signs to alert about congestion or lane closures in the Chicago area.

5 MINUTES TO CIRCLE

that's what I usually see - minutes vary greatly.

[hobsini2]

Yes they do give travel times too.  The travel time is the primary, accidents/congestion/amber alerts are secondary.

[Brandon]

Yes they do give travel times too.  The travel time is the primary, accidents/congestion/amber alerts are secondary.

But they are nowhere near as good nor as consistent as the Tollway.  They post travel times at all hours in both directions as well as messages.  IDiOT's main message at the VMS on I-55 Nbd at MP 255?  "Click It Or Ticket".  Really freaking useful.   

[vdeane]

That's actually NY's default message for EVERY VMS sign (though they phrase it "Buckle Up NY - It's the Law").

[hm insulators]

IIRC, I read a story maybe 5 or 6 years ago dealing with wrecks and gawkers.  I want to say it was the city of Pittsburgh that implemented a system of raising a giant portable curtain so that opposite-side drivers wouldn't slow down to gawk at wrecks.  I don't know any results of how well it worked in practice, but I thought it was a really clever idea to keep people focused on the road on both sides of the highway.

Nah.  'Round here, they'd still rubberneck at the damn curtain!

Once upon a time (and they could actually be using them), Caltrans had a plan to use these "gawk screens" along I-10 between Los Angeles and Santa Monica. (This was before I moved to Arizona in 2004.) When these screens were announced, my immediate reaction? "That ain't gonna work! People will just gum up the freeway to try to see through the screen!"

[hm insulators]

I've been seeing a lot of hot pink "accident ahead" signs lately...I think that is a Columbus PD thing though.  Usually they are used when there is a long term (hours) situation, rather than the odd fender bender.  I have seen some portable VMSes and even cones to close lanes, so I think the idea is out there if not everywhere yet.

Edit: this is it.  Apparently it is in the MUTCD...I'll be damned.

I didn't realize these signs go back to 2009. I saw one for the first time driving from Phoenix to San Jose in one fell swoop. I was approaching the I-10/California 60 split just west of Beaumont and the traffic started backing up. Just as I started rounding the final curve before the interchange, I saw the "ACCIDENT AHEAD" sign. Now the one I saw appeared to be orange rather than pink, but that's because I only caught a brief glimpse of it and it's possible that I'm mistaken as to the color. Anyway, I saw the traffic on my planned route, I-10, was jammed, so at the last instant, I bailed onto the 60.

[jeffandnicole]

Here's the deal with gawkers/rubbernecking, etc:  You can only go as fast as the car in front of you. 

So, let's say an accident happens on the NB side of the roadway, and Driver A driving SB slows down to look at it.  Driver B has to slow down also, and may slow down even more as they don't know how much Driver A will be slowing down.  Driver C has to slow down because Driver B has slowed down.  Driver D slows down.  Driver E and the thousands of drivers behind him must slow down too.  So how does one be at fault for slowing down when if they drove faster, they'd be ramming the vehicle in front of them?

The situation continues until the accident is cleared.  Slowly, traffic starts speeding up again, just like at a traffic light.  Not everyone speeds up at the same time when the light turns green - the vehicles must wait until the vehicle in front has started moving again.

Remember this - if you're mad at the guy in front of you for slowing down to look at the accident, don't worry - the guy behind you is mad at YOU for slowing down to look at the accident also!

[jeffandnicole]

What they should have done is open the zipper lane for the westbound side and set up a lane shift to deal with the merging, place a fleet of police cars on the bridge to ticket gawkers, change the VMS warnings from "expect delays" to "extreme delays", and setup more VMS signs to say that gawkers will be fined for impeding traffic.  Had they done this, the backup would have been much less severe, and I'm about to send them a nasty email to that effect.  But why don't agencies do this?

Unfortunately, this over simplifies how the system works. 

The Zipper Lane was open for travel in the EB direction at that time due to the historic heavier flow of traffic in that direction during that or the near future or recent time period (understand I'm just guessing since I don't know what time or day the incident occurred).  By closing that lane when it is needed only serves to congest the EB direction.  Additionally, driver expectations are such that they expect the barrier to be in that same position at the same time each day.  Motorists do not take well to a sudden change from the normal, and that's when other accidents can occur.

Moving on - Even if the barrier was to be moved, zipper barrier machines move at a crusing speed of around 7.5 mph - it takes 45 minutes to move that entire barrier.  And because the barrier machine is a diesel engine, they typically need several minutes to properly warm up - especially if the braking system is an air brake system. And then there's the before-mentioned issue of just getting an employee that can operate the machine to the machine (don't assume he's just sitting in the truck...he is most likely working elsewhere and can't just jump off that job).

As for the gawking issue, review my prior post.

As for the police issue, it's also an assumption that all the police are doing is sitting around looking for speeders.  Depending on the accident, most of the on-duty officers may have been responding to the accident.  Other officers may be kept positioned in case of a second accident, or dealing with another issue.  Compare it to this similiar situation: All firefighters at a burning building don't go rushing into the building.  Some of them are a part of a team that stays behind in case a firefighter needs to be rescued. 

It's easy to think what should have been done when you're the one stuck in the traffic.  But most procedures have been developed based on decades of experience.