Streetfilms: What’s an LPI?

A leading pedestrian interval, or LPI, lights up the pedestrian signal a few seconds before vehicular traffic gets the green. This gives pedestrians
a head start into the intersection and makes it less likely that they will be hit by vehicles turning into the crosswalk. LPI’s are also known by their sassier nickname, Pedestrian Head Start. But in my view the best variation on what LPI stands for comes from Christine Berthet of the Hell’s Kitchen Neighborhood Association, who proposes "Life Preserving Interval."

Transportation Alternatives has recently begun a push to make these more common in New York City. Here’s hoping our video (featuring some nice visuals from TOPP’s own Carly Clark) can help argue the case.

  • Stu

    The problem with LPIs is that they’re not standard, and so cars tend to creep into the intersection before the red light switches over, because they figure it’s their turn.

    So, like pretty much everything else streets-related, they can only be supremely useful if they’re enforced properly.

  • JK

    Congratulations on an excellent feature. This is really well done and a great resource for community groups. A couple more stats about how LPIs have been demonstrated to reduce the number of pedestrians struck would be nice.

  • Geck

    I have said it before, but it is worth repeating. The LPI at the Manhattan side of the the Manhattan Bridge is often used by traffic cops as an opportunity to wave cars onto the bridge notwithstanding the presence of pedestrians in the cross walk who have the walk signal. I cringe every time I see it.

  • I’ve noticed the LPI at a few intersections. It seemed effective. The bulk of walkers and some bikers get through the intersection before the turning cars back everything up.

  • Ian

    This may sound like a good idea, but it doesn’t add to pedestrian safefy, it just means that the ped meat will be further into the path of traffic before they are hit. What we need is a dedicated UK style signaling that brings all traffic entering the cross walk to a stop before the walk sign is lit. This means pedestrians and motorists don’t get the mixed signal of a green light but might still have a something to avoid in the road.

    We are programmed to go on green and sometimes we forget that green goesn’t mean go in the case of pedestrians and autos. It means proceed and hope that the other person is paying attention.

  • Is there any reason why this idea can’t be rolled out at all major intersections citywide, immediately? It certainly would make my daily life both safer and pleasanter.

  • Like Geck says: In the places I know of that have LPIs, the one thing that does make me madder then hell is when the traffic cops immediately wave the cars thru. Just today, a cop waved a car dangerously thru a field of pedestrians (who had the light) on Chambers Street and the woman cop yelled at a woman pushing a baby carriage, “You better watch it, you are gonna hit.” I mean is that valuing human life? Perhaps that will be a follow up Streetfilm, examining traffic cops behavior at intersections.

  • ddartley

    Traffic cops who wave cars through fields of peds:

    I wonder how much they’re following some directive to keep cars moving, and how much they’re making their own moment-to-moment judgment calls. I’d hope to see that question explored in a streetfilm on the subject (said the guy who doesn’t shoot films).

    In either case, such behavior shows that city officials–high ranking or low–value the convenience of motorist over pedestrian safety.

    Unfortunately, my observations suggest that too many pedestrians themselves seem to think that way also!

  • GM

    LPIs certainly come in handy in getting people out into the crosswalk. For me personally, I don’t find them a necessary feature, but some people are particularly nervous crossing and do that wave thing to let you go through even though they have the right of way. Once that happens the cars bunch up and accelerate and don’t stop so then it’s hard to get the pedestrian flow going again.

    Problem is though, that pedestrians follow blindly. If the crosswalk signal says to stop in order for a left turn car lane to flow, people continue to walk making it difficult to relieve the turning lane of traffic. (To make one example)

    My point is that we need more traffic cops. Both pedestrians and drivers are not being fair and sharing the roadway.

    Or less cars.

    Or more traffic enforcement. Pedestrians do have the right of way.

  • Mark, that’s a good question. the DOT plans to install LPI’s at 320 of the city’s 12,000 signalized intersections by 2010. question is: why not make them standard at all intersections, today? the obstacle is not cost, but the lengthy and rigorous analysis that the DOT does prior to installing them. why is this necessary? LPI’s save lives. install first, ask questions later.

  • StreetsPariah

    I’d like to see a reverse LPI, as in, the walk signs last after the light turns red. That way you wouldn’t have car creep, right?

  • gecko

    Curious there’s even a question about doing this?

    Since Commissioner Sadik-Khan has explicitly stated that the elderly and children are over-represented in current statistics broad implementation of leading pedestrian intervals is a perfect way to accelerate her expressed goal to halve current mortality and injury rates and effectively reduce the disparity in safety protections given to car drivers, their passengers, and the much more vulnerable walking public.

  • StreetsPariah: Great question — any of the more wonkishly inclined out there have an answer?



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