If a Diagonal Crossing is installed, but not visible?

As noted on the Endangered Pedestrians thread, Chapel Hill is testing an "exclusive pedestrian" traffic signal phase at the Columbia (NC 86) & Cameron intersection, a configuration of traffic signals and pedestrian "walk" displays that will allow those on foot to cross in all directions at once, including diagonally across the street.  This video (also below) demonstrates such a crossing in Los Angeles.

Visitors to Chapel Hill's implementation must be forgiven for not recognizing this new feature--the "Diagonal" concept was apparently done very lightly here.  Unlike the one in the film, ours has No Signs and No new Stripes.  The only indication of change was that all the push-to-cross buttons have been taped up to indicate that they are no longer functional.  But, indeed, when the "walk" phase comes up, all crossing lamps switch to "walk" simultaneously, while all the vehicular traffic lights go red.

Because the pedestrians were not notified that they may cross diagonally, they do not do so, but cross one street, turn 90 degs and cross the other.  Still, they're unencumbered by turning vehicles, which is an improvement.


I've been in other places that use this approach called the "Barnes Dance," named for the guy who implemented it in NYC and other places some years ago.

I walked by this intersection on the way to NRG forum the other night.  There was no evidence in the signal pattern of the Barnes dance interval.  There was no notification to pedestrians that they had the opportunity, if it existed.  More importantly, I did not see any instruction to motorists that pedestrians had the opportunity.Unless conditions are changed, I would not draw any reasonable conclusions from the "test of concept" at this intersection.  

If you float a trial concept, but don't tell anyone to try it, how can you tell whether it worked?

Even if this were an option, the defensive pedestrian would do well not to make themselves a target in so many directions at once!  This seems like going down an inappropriate path for our community.  It might be fun to think about and fun for the traffic engineers, but the defensive pedestrian who actually uses this would end up having to go to a chiropractor, what with having to monitor four directions at once, not to mention being wary of turn lanes and all the rest.  Maybe the town should have a fund for all the neck injuries that will ensue. The wikipedia article is instructive on this approach, aka the "pedestrian scramble":  http://en.wikipedia.org/wiki/Pedestrian_scramble.  As they say there, "The pedestrian scramble has both negative and positive aspects. It
requires that non-pedestrian traffic in all directions be stopped,
creating lost time for motorists and reducing an intersection's vehicular capacity,
although it may be mitigated by time gained removing pedestrian
directional signals (e.g. east-west and north-south). It is also often
difficult to ensure that an intersection is free of pedestrians at the
end of the scramble time. For these reasons,some traffic engineering
textbooks discourage the pedestrian scramble except in low-volume rural
and suburban intersections where there may be a safety benefit."  Anybody looked at any textbooks lately?

I disagree that "lost time for motorists" would be a net effect.  Consider traffic turning right from westbound Franklin to northbound Columbia: when the light is red, they're blocked by through vehicular traffic on Franklin.  As soon as the light turns green, westbound pedestrians get the "walk" on Franklin and begin crossing Columbia cutting off turning vehicular traffic.Cameron at Columbia is unusual in that ALL of the southbound traffic is turning.  Mostly, to the right. The very next paragraph in the Wikipedia article states:

However, intersections with high volumes of turning traffic as well as
high pedestrian volumes can greatly benefit from a pedestrian scramble.
Capacity decreases caused by lost time can be recaptured by eliminating
capacity decreases caused by right- or left-turning vehicles blocking
the intersection while waiting for pedestrians to cross.

Therefore, Columbia at Cameron and Columbia at Franklin are ideal spots for this type of crossing.

They don't call it a "scramble" and a "dance" for nothing.  Pedestrians are on their own, and they should always know this (and those who do probably know better how to dance and scramble than those who do not).  Having the right-of-way makes no nevermind against a multi-ton vehicle (or even a fast moving bicycle, which can cause serious harm, as well).  This sort of technical approach might help with efficiency in some respects, but one concern is that could lull people into thinking they might be any safer than otherwise.  When you cross, you had better know what each vehicle that could place you in jeopardy is going to do, and act to minimize all risks accordingly.  If this sounds out of whack, remember what those people are doing in theirs cars:  talking on their cellphones, chewing gum, adjusting the radio, even sending a fax, sending text messages, and all the rest.

A heads-up about the new light configuration would hvae been nice, but
the fact that this change has been implemented is enough to call things
even. I've been crossing this intersection for the past couple of
years, but only recently (perhaps due to increasingly agressive traffic
traveling north on Columbia) have I noticed how dangerous it was to
cross Cameron, as a pedestrian, along the western side of the square.
Far too many times have I seen drivers burst out of the blind corridor
of Columbia to come to a skidding halt (when one is lucky) when they
spot a pedestrian blocking a swift left turn onto Cameron. While it
can't be said for other intersections in our town, I'm glad it didn't
take any pedestrian deaths or injuries (to my knowledge) to get this

Part of the issue with those cars is that at that time, they have a green arrow.  In every other intersection, a specific green arrow means you have the right of way.  Here, it did not -- it meant you can turn left, but watch out for the ever-present pedestrians.  If you've never made that blind turn before, you're not thinking pedestrians, you have a green arrow only. 


My problem with the new arrangement is that it appears to be on 24x7.  Given that you can't turn right on red (southbound on Columbia), taking away the pedestrian "call buttons" for the cross signal will always be a drag on auto traffic during non-student times.

bring back crossing guards! (just don't arm them.) 

I work for a well known pizza delivery company so my weekend shifts are taken up with several jaunts to south campus and then back to the store.

Making a left from northbound on S. Columbia onto westbound Cameron Ave was the second trickiest traffic maneuver until the recent change. Previously, I had to watch for foot traffic going parallel to Cameron, then watch for pedestrians crossing Cameron with the pedestrian walk signal, and watch for other cars using the center lane which was both left turn and straight traffic.

The left turn option for the center lane is gone. Pedestrians don't have the go signal when left turning traffic has a green (I always thought I would get rear-ended by an unattentive motorist who did not notice the pedestrians ahead of me).

Traffic tends to get snarled up at that intersection now however. I have had to wait a couple of cycles trying to go west on Cameron (but that may have been because some event at Memorial Hall was letting out).

If the pedestrians have their own specific time when they can cross without vehicular traffic, there should be signs telling them that and telling them to wait for the signal which will come on automatically. But, if I needed to cross the south side of the intersection parallel to Cameron (you know, against the one way traffic) it would be a waste of time to wait for the pedestrian cross signal when traffic there is stopped for 2/3rd of the light cycle time. I have told pedestrians waiting on the corner that they could cross safely until the opposing lights turn yellow.




This is a great idea, but as often is the case around here (e.g., the sharrows on MLK), badly executed.  Signs and stripes are needed at this intersection. I don't see how this puts pedestrians at more risk.  They are crossing when there are red lights for autos in all directions.  Certainly it is more dangerous for people to cross when cars are turning across the pedestrian crosswalk.

Obviously, after UNC finals are over is no time to run an experiment of any type at the corner of S. Columbia and Cameron.  The test will really begin when classes  restart in January.  When is the experiment scheduled to end? 

From the Herald-Sun article:

The test phase will last approximately four to six
months. Traffic will be monitored during the peak hours of student
class attendance and high traffic periods, particularly in late
afternoon. If the town and DOT determine that the new phase is helpful
to pedestrians, it may be implemented at other high traffic

I believe the changes were made a week before Thanksgiving.

I haven't read through this whole thread, so I may be repeating something, but if you are wondering where to comment on this, it is a Town project.  I cross this interesection most days as it lies between my parking space and my office, and there is a wonderful feeling of independence and freedom to walk the diagonal.  I am the only person I've seen do it.  I keep waiting for someone to run up to me in concern and push me back to the crosswalks....As I said, I haven't read through the comments, so I don't know if people are loving this or hating it, but I have to say that I stand up straighter and breath deeper when I step off the curb at the Inn, heading for the diagonal corner.Linda C.  Linda Convissor

Linda wrote that "... there is a wonderful feeling of independence and freedom to walk the diagonal. I am the only person I've seen do it." Yes, it is a good feeling. I have been doing the Barnes dance -- walking the diagonal -- as well.James Coley

I have since read that until the signs go up the diagonal walk is illegal. 

Just want to clarify that my comment above that the diagonal walk is illegal wasn't meant to be anonymous.  I actually thought the post had disappeared into the ether and just now realized that it had posted, albeit anonymously.  Not that it's anything controversial, but I feel so strongly about posting anonymously (that it shouldn't be allowed) that I wanted to clear the air.Sometimes I forget the "how to" of posting and mess up. Linda Convissor

I moved here in August from New Haven, Conn., where nearly all intersections have this kind of crossing signal.  Mostly I liked it, but it requires a bit more waiting from all parties involved.  Sometimes I felt drivers resented waiting for pedestrians as a result.  The most annoying thing was that a pedestrian had to push the button in order to get the signal in nearly all intersections, and more than a few times people wouldn't realize this and would end up jaywalking anyway.  Other people thought by pushing the button the light would change immediately, and I've seen this at a couple of places around CH, too. Columbia/Cameon is an odd intersection, andI think it will work so long as they inform pedestrians and drivers very clearly about what's going on.  Putting duct tape all over the signal buttons does not do this.

Bruce Siceloff writes in the N&O:

Neppalli said new signs will be posted in the next week or so, urging pedestrians to cross only with the signal.And, for the time being, they're supposed to cross only one street at a time. The town said in a November news release that the new signals would allow pedestrians to cross the intersection diagonally while all vehicle traffic is stopped, but Neppalli said he does not yet have DOT permission for that.If DOT gives the nod, the town will install more flashing signs with pavement stripes for a big diagonal criss-crosswalk.

With proper signage and a certain crowd mentality, a diagonal crossing could work very well there.  But DOT might never grant permission for such a radical option.  We may have invented a brand new form of jay-walking!  Who needs pavement stripes when traffic is stopped in all directions?  That intersection is particularly hectic and potentially dangerous for pedestrians unless the cars are stopped for sure -- no right on red, half a minute to cross with confidence while the OK light is lit.  A month from now, just watch: people will cross every which-way just because they might as well.  Next up: the intersection at South Columbia & Manning Drive. 

Thing is, they're still allowing right-on-red, which (at least in theory) requires stopping first, and yielding to pedestrians.  From the November Herald-Sun article:

Kumar Neppalli, engineering services manager for the town, said drivers in three directions still will be able to make a right turn on the red light, but they must yield to pedestrians.

This should, however, eliminate the turn-on-green motorist/pedestrian conflicts.

If this experiment becomes permanent then the Town can (and IMO, should) petition DOT to allow 'No Turn On Red' signs to be posted at these intersections.  Too many drivers abuse that right and too many pedestrians assume that just because they have the walk sign that it is safe. 

You can't make a right on red going South (prohibited for while now). You can't make a right on red going West (Columbia one way there). How do you get "three directions" from the other 2 points of the compass?

I would love to see a few diagonal crosswalks around here.  The introductory phase would involve much more signage and flashing lights than I like to see, but public safety is paramount.  One or two intersections in Carrboro would be suitable for diagonal crossing.  All we need is for DOT to allow such a thing.  Any chance of that?   Happy Xmas Eve to all.  - c.  

Are flashing lights involved?  I haven't seen that.We should keep mind in that eliminating these conflicts helps motorists too, both those attempting to turn and through traffic waiting behind the turners.I do not understand the taping up of the push-to-cross buttons...perhaps the controllers can't handle this configuration? firmware upgrade needed? or it will take some time to reconfigure them? I think that Kumar Neppalli serves as traffic engineer for both Chapel Hill and Carrboro. In Carrboro, Greensboro at Weaver would seem to meet the "high volume of turning traffic as well as high pedestrian volume" criteria, with conflicts between pedestrians crossing Greensboro on the north side and motorists turning right from westbound Weaver to northbound Greensboro.  Similarly southbound Greensboro onto Roberson, and just about everything at Greensboro and Main.

Another issue at this intersection is two left turn lanes going north on south columbia. As a cyclist I find it tough to make the turn (and when I am in a car a number of drivers seem unclear about where the lanes are.)The intersection should be resigned so only the far left lane can turn left and the middle lane would be straight only. Ideally this stretch should be reduced from 3 lanes going north to two lanes. A wide right lane would make it easier for cyclists and buses.


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