Pedestrian interval times (2009 MUTCD gone too far?)

[tradephoric]

With an aging population, the new 2009 MUTCD pedestrian clearance intervals are calculated with a slower walking speed when compared to the 2003 edition (3.5 ft/sec vs. 4.0 ft/sec).  In addition, the new standards greatly increase the walk interval used when a pushbutton is set back from the actual crossing (under the 2003 MUTCD, a walk interval of 7 seconds was typical).  Some guidance is provided:

14   The total of the walk interval and pedestrian clearance time should be sufficient to allow a pedestrian crossing in the crosswalk who left the pedestrian detector (or, if no pedestrian detector is present, a location 6 feet from the face of the curb or from the edge of the pavement) at the beginning of the WALKING PERSON (symbolizing WALK) signal indication to travel at a walking speed of 3 feet per second to the far side of the traveled way being crossed or to the median if a two-stage pedestrian crossing sequence is used.  Any additional time that is required to satisfy the conditions of this paragraph should be added to the walk interval.

Looking at an example, an intersection with a side-street pedestrian crossing of 130 feet and a pushbutton 60 feet away from the crossing would lead to the following pedestrian intervals:

2003 Edition: Walk =  7 seconds.; Ped Clear Interval = 33 seconds; Total = 40 seconds
2009 Edition: Walk = 26 seconds; Ped Clear Interval = 38 seconds; Total = 64 seconds

In this particular example the new standards have increased the pedestrian intervals by 60%.  Does anyone feel that the new standards have gone too far and are leading to big increases in motorist delay?

[NE2]

Drivers only have themselves to blame for not allowing pedestrians to complete their crossing under the old intervals.

[Scott5114]

I think perhaps it may be due to pedestrian misunderstanding of the clear interval, i.e. not realizing that they can finish crossing during the blinking red hand and assuming that the signal expects them to make it all the way across the street in 7 seconds. 

[akotchi]

Assuming that the push button is placed correctly per ADA guidelines, the difference between the two conditions should not be too significant.  In the example above, the push button would need to be moved closer to the crossng.

[myosh_tino]

Drivers only have themselves to blame for not allowing pedestrians to complete their crossing under the old intervals.

Care to clarify that for us?

AFAIK, none of the pedestrian signals have been lengthened around here.  One particular signal I'm familiar with has a 4 second WALK phase followed by a 29 second flashing DON'T WALK phase.  It was like that before the 2009 MUTCD and it remains that way after.

Also, the city of San Jose is (was?) experimenting with a pedestrian crossing system will automatically shorten itself if it detects that there are no pedestrians in the crosswalk by using a pretty elaborate system of cameras.  For example, if a pedestrian is given 40 seconds to cross but crosses in 25 seconds, the system will detect that and end the flashing DON'T WALK prematurely (say at 30 seconds) and cycle the lights.  Not much has been said about this system since it was installed a couple of years ago but from what I recall, the system was pretty pricey due to the extra equipment.

[Alps]

3.5 feet instead of 4 feet is still a major bugabear, even with proper pushbutton placement.

[tradephoric]

Assuming that the push button is placed correctly per ADA guidelines, the difference between the two conditions should not be too significant.  In the example above, the push button would need to be moved closer to the crossing.

That's a very good point.  Any pushbutton greater than 10 feet from the crossing is already violating the guidance found in the 2009 MUTCD and hopefully engineering judgement would supersede the guidance when calculating pedestrian intervals at intersections where pushbuttons are farther than 10 feet away .

06   Where there are physical constraints that make it impractical to place the pedestrian pushbutton between 1.5 and 6 feet from the edge of the curb, shoulder, or pavement, it should not be farther than 10 feet from the edge of curb, shoulder, or pavement.

[akotchi]

3.5 feet instead of 4 feet is still a major bugabear, even with proper pushbutton placement.

No argument with that . . .

[NE2]

Drivers only have themselves to blame for not allowing pedestrians to complete their crossing under the old intervals.

Care to clarify that for us?

Too many drivers think green means that they don't have to look for conflicting movements before going. So a slow pedestrian might get trapped between lanes if they don't have enough time to cross.

[kphoger]

a 4 second WALK phase followed by a 29 second flashing DON'T WALK phase

This is what gets me.  There are a few intersections where I can't recall ever having seen the actual WALK phase, yet I've seen the flashing DON'T WALK counting down from more than 20.  And these are normal four-lane roads, maybe a left turn lane in the middle.  WTF?

Does anyone feel that the new standards have gone too far and are leading to big increases in motorist delay?

I think, if you walk at a much slower-than-normal speed, then you're already expecting to need a little more than the allotted WALK time anyway.  We don't need to be holding up traffic at every light cycle to accommodate toddlers holding their parent's hand, people with a cast on their leg, little old ladies using a walker.... Yeesh....

Drivers only have themselves to blame for not allowing pedestrians to complete their crossing

Amen.  When there's a slower pedestrian who hasn't quite made it across the street yet, the vast majority of drivers (a) have already assessed the situation, and (b) have no problem waiting a few extra seconds to let the person finish.  I've experienced this as a pedestrian plenty of times.

Once, I was walking in downtown Chicago with my (then) young daughter, on our way to catch a train at Union Station.  I had my suitcase, a pack-and-play, her backpack, a car seat, probably a couple of other things–plus, of course, her–and she was too scared to cross the street without holding my hand.  I didn't have a free hand.  Now what, right?  Believe you me, there was no way in Helsinki we'd make it across any intersection on a green light.  So what happened?  Everybody around understood the situation perfectly.  A random passerby helped us across a couple of intersections, drivers waited patiently, and everything was A-OK.

It's been my experience that the people who get "caught out" in between lanes when the other light turns green are those who are perfectly able to cross in time, yet chose to start across the street right when the light was turning yellow.  Motorists are less likely to accommodate someone like that.

[myosh_tino]

a 4 second WALK phase followed by a 29 second flashing DON'T WALK phase

This is what gets me.  There are a few intersections where I can't recall ever having seen the actual WALK phase, yet I've seen the flashing DON'T WALK counting down from more than 20.  And these are normal four-lane roads, maybe a left turn lane in the middle.  WTF?

The 20-second DON'T WALK phase sounds about right to me for the intersection you describe...

5 lanes x 12 ft per lane = 60 ft + 2 ft median + 6 ft shoulders (3 each) = 68 ft total width.

At 3.5 seconds per foot, that comes to 19.4 seconds which is close to the 20 seconds you stated.

In California, pedestrians may not only enter an intersection when the WALK symbol appears.  The flashing DON'T WALK is essentially the time a pedestrian in the crosswalk has to clear the intersection (at the 3.5 seconds per foot rate).

Of course with the advent of the countdown timers, if a pedestrian knows he/she can clear the intersection within the displayed time remaining (running, walking really fast, etc), I don't have a problem with them entering the intersection during the flashing DON'T WALK as long as they clear the intersection in time.

[kphoger]

a 4 second WALK phase followed by a 29 second flashing DON'T WALK phase

This is what gets me.  There are a few intersections where I can't recall ever having seen the actual WALK phase, yet I've seen the flashing DON'T WALK counting down from more than 20.  And these are normal four-lane roads, maybe a left turn lane in the middle.  WTF?

The 20-second DON'T WALK phase sounds about right to me for the intersection you describe...

5 lanes x 12 ft per lane = 60 ft + 2 ft median + 6 ft shoulders (3 each) = 68 ft total width.

At 3.5 seconds per foot, that comes to 19.4 seconds which is close to the 20 seconds you stated.

12 feet seems pretty wide a lane on a city street.  Isn't that the normal width for an Interstate highway lane?  Anyway....

In California, pedestrians may not enter an intersection when the WALK symbol appears.

Is that a typo?  Should it be "when the DON'T WALK symbol appears"?

[myosh_tino]

In California, pedestrians may not enter an intersection when the WALK symbol appears.

Is that a typo?  Should it be "when the DON'T WALK symbol appears"?

Yep, that's a typo and it's been corrected in my post.  Thanks.

[Alps]

Of course with the advent of the countdown timers, if a pedestrian knows he/she can clear the intersection within the displayed time remaining (running, walking really fast, etc), I don't have a problem with them entering the intersection during the flashing DON'T WALK as long as they clear the intersection in time.

This has actually been added to the MUTCD

[tradephoric]

An important point to be made is that the pedestrian change interval (FLASHING DON'T WALK indication) is not the same thing as the pedestrian clearance interval.  Under the new standards a buffer interval must be provided so that a solid UPRAISED HAND is displayed for 3 seconds prior to the release of any conflicting vehicular movement but this value can be subtracted from the FDW time.  This might show it clearer:



The triple asterisk (***) states that the buffer interval may be used to help satisfy the calculated pedestrian clearance time, or may begin after the calculated pedestrian clearance time has ended.  For simplicity, a lot of agencies decide to begin the buffer after the calculated time has ended which leads to longer pedestrian times than required.  This wouldn't be a big deal if we're only talking 3 seconds but the buffer can be much larger (the new standard has no upper limit to how high the buffer can be).   

The problem is the majority of traffic signal controllers are unable to provide an exact  3 second buffer.  For an EPAC controller there are only three options to terminate the flashing don't walk indication (known as Extended Pedestrian Clearance Codes):

Code "0"  This is the standard NEMA TS 1 & TS 2 defined pedestrian operation.
Code "1"  The Pedestrian Clearance Interval (Flashing Don't Walk), for a phase so programmed, may time concurrently with the Vehicle Change (Yellow Change + Red Clear) intervals.
Code "2"  (Extended Pedestrian Clear): Similar to Code "˜1' except the flashing period (Pedestrian Clearance) may appear concurrently only with the vehicle Yellow clearance interval.

NOTE:  The Pedestrian Clearance Interval is NOT the same thing as the Flashing Don't Walk time and the definitions described in the EPAC manual are inaccurate.  By reading these definitions, some agencies may mistakenly believe they are violating the 2009 MUTCD when subtracting the buffer from the Flashing Don't Walk time.

Since selecting a pedestrian clearance code of 1 or 2 would often lead to a buffer interval of less then 3 seconds (since an all red of 1.5 - 2.5 seconds is very common), many agencies will choose a pedestrian clearance code of 0 across the board for simplicity (which terminates the flashing don't walk at the end of the green).


To tie everything together let's compare how different engineers might calculate the pedestrian intervals for the following intersection (in this example there is a natural 4 second buffer due to the trail green time):

• Pedestrian crossing distance = 140 feet
• Distance from pushbutton to crossing = 10 feet
• Yellow time = 4.7 seconds
• All red time = 2.3 seconds
• Trail green time = 4 seconds (to clear traffic from the intersection in a near/far setup).

OLD ENGINEER (calculates using the old 2003 MUTCD)
Walk   = 7 seconds         (normal minimum walk time not based on any calculations)
FDW   = 35 seconds       (140 ft / 4 ft per sec)
Buffer = 4 seconds      (extend ped clear =1; buffer = trail green)
Total   = 7 + 35 + 4 = 46 seconds

SIMPLE ENGINEER (2009 MUTCD, doesn't subtract buffer, extend ped clear always equals 0).
Walk   = 10 seconds      [(140 ft + 10 ft) / (3 ft per sec)] — (140 ft / 3.5 ft per sec)
FDW   = 40 seconds      (140 ft / 3.5 ft per sec)
Buffer = 11 seconds      (extend ped clear = 0; buffer = trail green + yellow + all red)
Total   = 10 + 40 + 11 = 61 seconds

BY-THE-BOOK ENGINEER (2009 MUTCD, subtracts buffer, extend ped clear code will vary)
Walk   = 10 seconds         [(140 ft + 10 ft) / (3 ft per sec)] — (140 ft / 3.5 ft per sec)
FDW   = 36 seconds       [140 ft / 3.5 ft per sec] — 4 second buffer
Buffer = 4 seconds      (extend ped clear = 1; buffer = trail green)
Total   = 10 + 36 + 4 = 50 seconds

[NE2]

Of course with the advent of the countdown timers, if a pedestrian knows he/she can clear the intersection within the displayed time remaining (running, walking really fast, etc), I don't have a problem with them entering the intersection during the flashing DON'T WALK as long as they clear the intersection in time.

This has actually been added to the MUTCD

Seems like the same as before:
"A flashing UPRAISED HAND (symbolizing DONT WALK) signal indication means that a pedestrian shall not start to cross the roadway in the direction of the signal indication"

[roadfro]

With an aging population, the new 2009 MUTCD pedestrian clearance intervals are calculated with a slower walking speed when compared to the 2003 edition (3.5 ft/sec vs. 4.0 ft/sec).  In addition, the new standards greatly increase the walk interval used when a pushbutton is set back from the actual crossing (under the 2003 MUTCD, a walk interval of 7 seconds was typical).  Some guidance is provided:

14   The total of the walk interval and pedestrian clearance time should be sufficient to allow a pedestrian crossing in the crosswalk who left the pedestrian detector (or, if no pedestrian detector is present, a location 6 feet from the face of the curb or from the edge of the pavement) at the beginning of the WALKING PERSON (symbolizing WALK) signal indication to travel at a walking speed of 3 feet per second to the far side of the traveled way being crossed or to the median if a two-stage pedestrian crossing sequence is used.  Any additional time that is required to satisfy the conditions of this paragraph should be added to the walk interval.

Looking at an example, an intersection with a side-street pedestrian crossing of 130 feet and a pushbutton 60 feet away from the crossing would lead to the following pedestrian intervals:

2003 Edition: Walk =  7 seconds.; Ped Clear Interval = 33 seconds; Total = 40 seconds
2009 Edition: Walk = 26 seconds; Ped Clear Interval = 38 seconds; Total = 64 seconds

In this particular example the new standards have increased the pedestrian intervals by 60%.  Does anyone feel that the new standards have gone too far and are leading to big increases in motorist delay?

I think you're misinterpreting that guidance such that your walk time calculation is severely overestimated...

MUTCD guidance only states that the walk interval is provided for pedestrians to begin their crossing, and doesn't make mention of calculations or walking speed for the walk indication.  The guidance you cite above basically says that the sum of the walk interval and pedestrian clearance time (FDW + Buffer) must be greater than or equal to the time it would take to cross the intersection at 3 fps.

Using the same intersection as above:
Crossing a 130-ft intersection takes 37.1 sec at 3.5 fps (round up to 38). Same intersection takes 43.3 seconds to cross at 3 fps (round to 44). Assume the recommended 7-second walk phase and 3-second minimum buffer.

2009 MUTCD requirement: 7+38+3 = 48 seconds crossing time prior to release of conflicting traffic. This exceeds the 44 seconds required from the guidance.

[kphoger]

My point about the 20+ second flashing DON'T WALK stems from a general feeling about the meanings of WALK, flashing DON'T WALK, and steady DON'T WALK.  I fully realize these are not the official meanings as stated by law, but I think this is what they generally denote to Joe Pedestrian:

WALK - Go ahead and cross.  You have plenty of time.  No worries.

Flashing DON'T WALK - Go ahead and cross, but you should hurry, since it will turn red soon.  In fact, why don't you go ahead and trot, jog, run?

Steady DON'T WALK - Don't cross the street.  Unless you do it at an absolute sprint.

What I'm saying is that I think most people treat WALK and flashing DON'T WALK almost the same.  I think this makes sense, since the traffic light is still green while the DON'T WALK is flashing and, in the absence of pedestrian signals, one would be permitted to start across the street at any point during the green light cycle.  So I find it silly to display what is realistically an almost meaningless signal for more than 20 minutes seconds.  I would naturally prefer a longer WALK signal followed by a shorter flashing DON'T WALK signal (though admittedly longer than a yellow light phase).  But, that would definitely not accommodate elderly or handicapped pedestrians.

[/end rambling]

[roadman]

Of course with the advent of the countdown timers, if a pedestrian knows he/she can clear the intersection within the displayed time remaining (running, walking really fast, etc), I don't have a problem with them entering the intersection during the flashing DON'T WALK as long as they clear the intersection in time.

This has actually been added to the MUTCD

Seems like the same as before:
"A flashing UPRAISED HAND (symbolizing DONT WALK) signal indication means that a pedestrian shall not start to cross the roadway in the direction of the signal indication"

That is correct.  The original NPA for the 2009 MUTCD included language to change the meaning of flashing don't walk, but that proposal was removed from the final version.

[tradephoric]

Here is the new standard that talks about the 3 second buffer in its entirety:

04   A pedestrian change interval consisting of a flashing UPRAISED HAND (symbolizing DONT WALK) signal indication shall begin immediately following the WALKING PERSON (symbolizing WALK) signal indication.  Following the pedestrian change interval, a buffer interval consisting of a steady UPRAISED HAND (symbolizing DONT WALK) signal indication shall be displayed for at least 3 seconds prior to the release of any conflicting vehicular movement.  The sum of the time of the pedestrian change interval and the buffer interval shall not be less than the calculated pedestrian clearance time (see Paragraphs 7 through 16).  The buffer interval shall not begin later than the beginning of the red clearance interval, if used.

At least a 3 second buffer interval consisting of a steady Upraised Hand must be displayed before the release of any conflicting vehicular movement but there is no mention to the longest buffer that can be used.  Since EPAC controllers are unable to provide an exact 3 second buffer much longer buffers are being selected. 

Assume the following EPAC controlled intersection with an extend pedestrian clearance code of 0 being used (terminates the FDW at the end of green).
-   Pedestrian crossing distance = 70 feet
-   Distance from pushbutton to crossing = 10 feet
-   Yellow time = 4.7 seconds
-   All red time = 2.3 seconds
-   Trail green time = 4 seconds (to clear traffic from the intersection in a near/far setup).

The pedestrian clearance interval in this example would be 70 ft / 3.5 ft per sec = 20 seconds.  The 11 second buffer (4.7 second yellow + 2.3 second all red + 4 second trail green) can be subtracted from the calculated pedestrian clearance interval to determine the appropriate pedestrian change interval (Flashing Don't Walk). 

The sum of the time of the pedestrian change interval and the buffer interval shall not be less than the calculated pedestrian clearance time.

The sum of the 9 second pedestrian change interval (Flashing Don't Walk) and the 11 second buffer interval is equal to the calculated pedestrian clearance interval of 20 seconds.  However, a pedestrian who steps out into the crossing just as the 9 second Flashing Don't Walk begins would have to average 7.77 ft/sec to complete the 70 foot crossing before the Flashing Don't Walk terminates.

[Alps]

Of course with the advent of the countdown timers, if a pedestrian knows he/she can clear the intersection within the displayed time remaining (running, walking really fast, etc), I don't have a problem with them entering the intersection during the flashing DON'T WALK as long as they clear the intersection in time.

This has actually been added to the MUTCD

Seems like the same as before:
"A flashing UPRAISED HAND (symbolizing DONT WALK) signal indication means that a pedestrian shall not start to cross the roadway in the direction of the signal indication"

That is correct.  The original NPA for the 2009 MUTCD included language to change the meaning of flashing don't walk, but that proposal was removed from the final version.

Damn. I can't believe they removed that.

[tradephoric]

I think you're misinterpreting that guidance such that your walk time calculation is severely overestimated...

MUTCD guidance only states that the walk interval is provided for pedestrians to begin their crossing, and doesn't make mention of calculations or walking speed for the walk indication.  The guidance you cite above basically says that the sum of the walk interval and pedestrian clearance time (FDW + Buffer) must be greater than or equal to the time it would take to cross the intersection at 3 fps.

The guidance I cited is based directly on paragraph 14 of the MUTCD.  I bring this topic up again after a recent trip to Vegas where I was surprised to see only a 4 second walk crossing Las Vegas Blvd. & Bellagio Drive (145 ft crossing).   

Assuming you are following paragraph 14 guidance and subtracting the buffer from the FDW times, these are the times I get for this crossing. 

Walk = 9 seconds
FDW = 36 seconds
Buffer = 6 seconds (yellow & all red)

36 + 6  > (145 / 3.5)   <-satisfied Paragraph 7
(9 + 36 + 6 > [(145 + 6) / 3] <- satisfied Paragraph 14

Are agencies ignoring paragraph 14 of the MUTCD (it is only guidance after all) to improve vehicle capacity at intersections?  I don't understand the purpose of paragraph 14 and hoping to find some clarity. 

Thanks

[Duke87]

Of course with the advent of the countdown timers, if a pedestrian knows he/she can clear the intersection within the displayed time remaining (running, walking really fast, etc), I don't have a problem with them entering the intersection during the flashing DON'T WALK as long as they clear the intersection in time.

This has actually been added to the MUTCD

Seems like the same as before:
"A flashing UPRAISED HAND (symbolizing DONT WALK) signal indication means that a pedestrian shall not start to cross the roadway in the direction of the signal indication"

That is correct.  The original NPA for the 2009 MUTCD included language to change the meaning of flashing don't walk, but that proposal was removed from the final version.

Damn. I can't believe they removed that.

It doesn't really matter what the MUTCD says in this case so much as it matters what state laws say - i.e., can a cop ticket you for jaywalking if you start crossing on the flashing hand?
(ticketing for jaywalking is retarded no matter the circumstance, but that's a separate argument)

When there's a slower pedestrian who hasn't quite made it across the street yet, the vast majority of drivers (a) have already assessed the situation, and (b) have no problem waiting a few extra seconds to let the person finish.  I've experienced this as a pedestrian plenty of times.

There is a responsibility on the part of both the pedestrian and the motorist in any case where the former is in the latter's path. The motorist, of course, must yield to the pedestrian (running people over is bad). The pedestrian, however, should be alert enough to realize if he's holding someone up and move his ass out of the way if he is. If I'm crossing the street and I see a car looking to make a turn into where I am, I run until I am out of his path. Meanwhile, if I am the driver in that situation and the pedestrian continues just leisurely ambling along, I get pissed off. He's needlessly holding me up with his slowness.

[roadfro]

The guidance I cited is based directly on paragraph 14 of the MUTCD.  I bring this topic up again after a recent trip to Vegas where I was surprised to see only a 4 second walk crossing Las Vegas Blvd. & Bellagio Drive (145 ft crossing).
<...>
Are agencies ignoring paragraph 14 of the MUTCD (it is only guidance after all) to improve vehicle capacity at intersections?  I don't understand the purpose of paragraph 14 and hoping to find some clarity. 

I'm having a bit of issue thinking that there's only 4 seconds of walk time at a signal on the Strip...Although with the way people cross, maybe FAST just put a short time because people are going to violate the ped heads no matter what they do.

Without researching specifics, I couldn't tell you what the guidance in that paragraph 14 is getting at either. Many agencies weren't too keen on the reduced walking speed to be used in calculations of pedestrian phases...it's conceivable that some might be ignoring this.

It's also conceivable (although rather unlikely) that FAST hasn't updated timing for this signal since the 2009 MUTCD was adopted, and could be operating on the old calculation rules.

[NE2]

It doesn't really matter what the MUTCD says in this case so much as it matters what state laws say

In Florida:
A pedestrian shall obey the instructions of any official traffic control device specifically applicable to the pedestrian unless otherwise directed by a police officer.
When pedestrian indicators are installed, such indicators must conform to the requirements of the most recent Manual on Uniform Traffic Control Devices.