Wednesday, June 10, 2015

Margin Of Safety


Pine Street, North Amherst

The Amherst Planning Board is unhappy with the final design for three crosswalks on Pine Street in North Amherst, citing the 8 foot width as too narrow and requesting the Select Board -- who has final say -- make them at least 12 feet wide.

Town Manager Musante dismissed the concerns telling the Select Board he's comfortable with the current 8 foot wide design and other assorted measures including a  high tech solar powered Rectangular Rapid Flash Beacon at each crosswalk.

 Transportation Plan seems to prefer 12 feet wide but did call this a "sample"

The town currently has no crosswalks greater than 8 feet wide.  And some are only 6 feet. The Select Board decided not to change the crosswalk plans at this late date.

 Crosswalks in town center are 8 feet wide

10 comments:

Anonymous said...

Pity the people using this crosswalk as cars speed down the street, especially at night. The town rarely enforces the speed limits. Why not give them some extra footage on the crosswalk? The streets are not just for cars.

DaveMB said...

Your picture doesn't show the Pine/State intersection, which is out of view to the top.

Dr. Ed said...

The problem with making crosswalks wider is that you dilute the concentration of a trained driver who is looking in a specific place for a specific thing -- if your crosswalk gets too wide and you only have a single pedestrian starting to cross, it becomes possible for a driver to focus in the crosswalk and not see the pedestrian, particularly someone small (e.g. child), and particularly at night when (with low beams) all you are going to see are feet and the first 18" of legs.

What I was taught (by the Maine State Police and others) was to specifically look at two specific places on each crosswalk -- first to the right where the nearest line of the crosswalk meets the edge of the road, then to the left where the nearest line crosses the center of the road, and then back to the first place.
On the right, I was told to focus on a square that followed the nearest crosswalk line out about 6'-8', not to look for the second line but go back that far. On the left it is a square the same size except straddling the center line -- and to both look for a stopped oncoming vehicle *and* see if the left tire is straight or turned toward me (the latter indicating a vehicle instead waiting to turn left).

Same thing as with my mirrors, you don't look at everything but at/for specific things and say "yes/no" -- there is/isn't a pedestrian there. While I will never forget what one police officer (riding with me) once said: "Ed, it is "pedestrian in a crosswalk" -- you do NOT stop for someone standing on the sidewalk. For all you know, he is [doing something vulgar]."

The reason why you do this is that you don't have enough time to process all the information. In a school bus, you have upwards of 72 "distractions" sitting behind you, driving an emergency vehicle, you can be closing on the next mile marker almost every 45 seconds -- if you look for everything, you will see nothing.

It's the same thing when you see 4-way flashers go on in front of you -- you (A) start downshifting to slow down, (B) put yours on, and THEN (C) figure out what the problem is and what you are going to need to do. A big truck can neither stop as quickly as a car nor really use its brakes to do so (they will quickly overheat) and hence you need to both start slowing down *and* warn the trucks behind you to do likewise *before* you have any idea why you need to. You may have been half asleep as well -- you legally are allowed to drive 10 hours/500 miles a day and many guys drive a lot more than that...

Hence if you make the crosswalk too big, you run the very real risk of someone being in it and still not being seen. The purpose of a crosswalk in the first place was to restrict the places where a pedestrian might be (as opposed to anywhere on the road) and if you make it too big, you are essentially defeating the purpose of a crosswalk. And white paint is VERY slippery when wet, particularly the good hot-applied plastic paint that stands up to traffic. Throw in the fact that if a drop of oil is going to fall off the bottom of an engine or transmission, it will do so when the vehicle is stopping or starting and hence oil tends to accumulate before crosswalks and you quickly get into situations where a motorist is unable to stop and doesn't know it until he/she/it tries to...

Dr. Ed said...

As to those damn flashing yellow lights -- well the bright yellow signs that UMass put up were bad enough -- directing the motorist's attention up 7 feet off the ground when you need to be looking no more than 18"-24" above the ground, but at least they are not distracting the way these damn things are.

Bluntly, I call them "Pedestrian Killers."

Why do we not let businesses put bright flashing signs on the side of dark roads? Why do we ONLY permit emergency vehicles to have flashing lights on them?

These signs are distracting -- they command attention, yes, but they take the driver's attention away from what you want him/her/it to be looking for, which is a pedestrian.

And as we all know that the police don't enforce crosswalks at night during rainstorms, that is when the pedestrians get hit. Larry, ask the AFD to give you a list of pedestrian accidents and look up the weather conditions at the time -- wet road, at night, in lousy weather.

Throw in the fact that wet pavement exacerbates the blinding effect of bright yellow lights, and you have a bigger problem. Crosswalk or not, most people who hit a pedestrian "never saw him/her/it."

Larry Kelley said...

Dave: Just drove by and that is State Street off to the right. Out of view to the top would be North Pleasant and Pine Street intersection aka North Amherst Village Center.

Anonymous said...

Sorry, Larry - that's the entrance way to the Sunwood Pines condo complex at the right.

Anonymous said...

It's a matter of perspective - literally. A crosswalk appears narrower the farther you are from it. When cars are going faster (as on the straightaway section of Pine Street) you get more advance notice with a wider crosswalk as it appears larger.

I agree with "Dr. Ed" that the flashing lights are very dangerous. What is needed is bright, non-glare overhead lighting at the crosswalk, and NONE anywhere for say 100 feet either side, so that the peds themselves are lit up like neon f'n signs at night. And the current LED lights on Pine Street are HORRIBLE -they give horrendous glare to hte point of needing to use the sun visor at night. The dark stretches of road in between are pitch black. In my opinion the crosswalk Must be directly under one of those lights, but what do I know.

Anonymous said...

All the LED street lights recently installed in town need lenses or "shades" to direct them downward, and diffusers to cut the glare - they're a disaster waiting to happen, and maybe already were a contributing factor in a pedestrian fatality on East St last year.

Anonymous said...

I don't suppose it would ever come to pass that we give right of way to vehicles rather than pedestrians. Imagine all the gas we'd save if we didn't have to sit in these montrous rhings burning gas while we wait for granny and others to cross the street.

Dr. Ed said...

I wonder if it is more than just glare from the LEDs. LEDs are diodes, one-way valves for electricity and hence they work on DC.

AC is a sine curve, and a diode will let one half of the sine curve through, but not the other -- that's why your car alternator has to have two of them -- actually six because your alternator actually produces 3 phase AC which the six diodes make into DC.

Remember that + and - switch 60 times EACH second, it is a sine curve which the LED will only let half thorough, with light emitted when it does -- Light Emitting Diode...

Electricity won't go the other way through the diode, so is the other half of the curve rerouted to go through as well, or is it not? If not, the light is off half the time, actually a bit more than that because 120 times a second, voltage equals zero (for an incredibly brief instant before starting in the other direction).

The voltage equals zero is the flicker in florescent lights, but they produce light when electricity is going the other way as well. If the LED streetlights don't, while 1/2 of 1/60 of a second is still to brief a time for people to notice, if you are moving, it is long enough for you to be in a different place when the light returns than where you were when it went out and the human eye is not designed to deal with that.

The brain then "sees" what it expects to see -- an empty pedestrian free road and BANG... Remember that all of us have a blind spot in each eye -- where the optic nerve is and the brain just ignores that (along with the image being upside-down) and just automatically corrects the image.