A new policy to add leading pedestrian intervals (LPIs) is a step in the right direction by NCDOT. This signal timing gives pedestrians a head start into crosswalks, making them more visible to motorists who wish to turn across the pedestrian's path. The walk signal turns on ~5 seconds before the parallel traffic light turns green.
But it's a partial solution to a symptom of a much greater problem. 🧵
https://www.ncdot.gov/news/press-releases/Pages/2024/2024-07-26-pedestrian-safety-crosswalks.aspx
Across most of the US, it's legal for drivers to turn right on red, even when that means crossing a crosswalk with an active 'walk' signal. In theory, you are supposed to check for pedestrians...
...but driving is hard, and in reality most drivers are really bad at it, and they don't look to their right before turning right, which means they don't see the pedestrian lawfully in the crosswalk before hitting them. (3/13)
The LPI does nothing in this situation, because allowing right turns on red (#RTOR) negates the head start. Banning RTOR is the only way to ensure that pedestrians get to take full advantage of the LPI.
Some cities have tried selectively prohibiting RTOR at intersections with known safety issues. It's a good start, but compliance tends to be poor because humans don't like following conditional rules. It's going to take full scale ban to change driver behaviors. All or nothing. (4/13)
The other issue is that it's also common in the US to allow drivers to turn left across crosswalks with active walk signals. Sometimes we do this with a permissive left, which is a flashing yellow arrow that says to drivers, "it's up to you."
Permissive lefts are typically used on multi-lane roads. Drivers who wish to turn left must identify a safe gap in on-coming traffic, and when they see one they think they can fit through, they can go for it. (5/13)
Trouble is, driving is hard and most drivers are really bad at it, and the cognitive burden of identifying a safe gap in multiple lanes of on-coming traffic is pretty heavy, and our real, rational fear of getting clobbered by other vehicles makes us forget we also need to be looking to make sure we don't clobber any pedestrians...pedestrians who are lawfully in the crosswalk on the far side of the intersection. (6/13)
If said pedestrians are speedy, the LPI may give them enough of a head start to get out of the way of potential left turners. But not all pedestrians are athletes. Just like drivers, many pedestrians are old, young, creaky, carrying heavy stuff, and/or distracted. Five seconds is not enough for them to get to safety, especially when there are multiple lanes to cross. (7/13)
If permissive lefts aren't bad enough, some intersections actually give left turning motorists protective lefts--green left arrows--when there's an active walk sign in the path of the left turning motorist. IMHO, this is even worse. Here's why:
A green left arrow evokes a sense of priority and privilege among drivers. "This is my special green arrow. Nobody can stop me now."
But driving is hard and most drivers are really bad at it. So when we get a special signal just for us... (8/13)
...we're happy to give our overworked brains a moment's rest, and let the signal do the thinking. Yeah, sure, the law says we also have to be paying attention to our surroundings, but turning left is hard and our brains are tired. The light says we can go, so we can go.
Except sometimes there's also a light telling a pedestrian they can go. (9/13)
And that pedestrian is now in a stand-off with a driver who's just been told that this is their special time to go, and no one is supposed to be in their way. At best, they see the pedestrian and honk, yell, generally get pissy about it, but at least they probably don't hit them.
At worst, they don't see the pedestrian at all because the green arrow told them they didn't even have to look. And they are totally baffled to discover that they just hit someone and it was their own fault... (10/13)
...because they had a green left arrow.
Absent other interventions, #LPIs work best when:
1. pedestrians are fit, attentive, and ready to bolt when they walk signal comes on, and
2. right-turning drivers come to a full stop and look both ways before turning right, and
3. left-turning drivers are capable of managing an intense cognitive load and valuing the safety of others as much as their own
which is to say, very rarely.
What works is fully protected walk phases. (11/13)
Completely remove the possibility that a driver will have to navigate around a pedestrian who is lawfully in a crosswalk. No #RTOR, ever. No lefts--permissive or protective--across a crosswalk with an active walk signal.
Do that, and the #LPI becomes irrelevant. And walk signals will mean it's actually safe to walk.
But doing that takes willingness to prioritize #SafetyOverFlow. And we're not there yet. (12/13)
Don't get me wrong -- I'm happy our state transportation agency is taking this step. It's a big change, and they should be proud to have made it happen. This is good news and, hopefully, represents the start of a much needed shift in transportation policies.
But we still have a long, long way to go before we see meaningful improvements in how we think about and provide for anyone outside a car.
#Traffic #RoadSafety #VisionZero #pedestrians #CarSupremacy (13/13)
I am not a fan of LPI.
In nyc, LPI become known to drivers and since NY state limits the number of automated red light cameras— and many of our intersections have through traffic (higher volumes) in one direction of the signal— there is 0 risk to cars running the red light. No risk of a ticket. No risk of damage by other cars.
I’ve been meaning to do red light runner counts (during LPI) in my neighborhood. It is nearly every signal turn that light running happens during rush hrs.
@DrTCombs Hi ! I'm from Europe, and if from what I read in your account and elsewhere infrastructures in North America is REALLY REALLY bad, it also seems that people driving are equally bad. I mean we also have people crossing signal parallel to the driving signal turning green at the same time, and collisions are quite rare because people in car actually look before turning in thoses cases. Is the driving permit more easy to have or something in NA that could explain that skill difference ?
@DrTCombs I'm sorry if the wording is poor but I use to cycle and drive a lot and find all this very curious (but not in a good way)
@Zatsu We have a combination of factors working against us here.
Our infrastructure is bad because it's not designed with safety as a priority. Traffic flow is number one factor in our designs; any other needs have to be shoehorned in where they can.
We also don't have a culture of safety when it comes to road users. Other countries might call this a 'duty of care.' Here, we're all in it for ourselves. Life, Liberty, and Pursuit of Getting Ahead of the Next Guy.
@Zatsu So, infrastructure that's not designed to encourage safe behaviors + drivers who aren't programmed to think about safe behaviors + an unfounded belief that our systems are meant to protect us = 43,000 fatalities a year.
@Zatsu @DrTCombs A driver’s licence is really easy to get and keep. Where I live, a 14 year-old can drive with another driver in the vehicle. A 16 year-old can get a full licence. No requirement to retest until 75 or so.
Also, the infrastructure is generally great, but only for vehicles. In fact, infra is too good as it allows excess speed and inattentiveness. It would work great if everyone was a great driver, followed the rules, and there were no pedestrians
@Zatsu @DrTCombs Portugal - also in Europe - has a lot of drivers who do not take such precautions.
In Lisbon, it's not rare to see drivers almost murdering people because they think the non-red light gives them full priority. Couple this with high speeds, and what you have is infrastructure that basically discourages moving around on foot.
Yes, with these drivers the only solution is for the infrastructure to prevent both cars and pedestrians being allowed through the same spot.
@DrTCombs I love this thread and agree 100%. Everyone assumes that when they have a light that means there are no conflicts, and if there are, something is wrong with the signal. And they're right, as you expertly explain!
@DrTCombs We now have several intersections in our town that have a “pedestrian only, in any direction” phase: all vehicle lanes have red lights, no rights-on-red are allowed, and pedestrians have about 30s to cross, or to walk diagonally across the intersection if they want. Seems to work ok, and as a pedestrian, it is much less stressful. I don’t think it’s made much difference to drivers’ wait times, and drivers also benefit from not having to spot/dodge pedestrians.
LPIs improve intersection safety much the same way large print menus improve eyesight. Which is to say they are useful and better than nothing. But they do nothing to address the underlying issue.
The underlying issue is, at most signalized intersections in the US, a 'walk' signal does not mean it's safe to walk across the intersection. It means that if you get hit while you are walking across the intersection, it's legally not your fault (presuming your body lands in the crosswalk). (2/13)