Traffic Rant 235 lights

MiddleGround

Well-Known Member
The problem isn't the traffic lights at all. It's the idiots who won't put their cell phones down for a 15 minute drive home.
Although the cellular idiots are a definite hindrance to the flow of traffic, I would have to disagree with you that traffic lights are not the problem.

If you drive up and down 235 daily, you can see how the lights (and overall road design and planning) is very poor to handle the traffic flow during morning and afternoon rush.
 

glhs837

Power with Control
Although the cellular idiots are a definite hindrance to the flow of traffic, I would have to disagree with you that traffic lights are not the problem.

If you drive up and down 235 daily, you can see how the lights (and overall road design and planning) is very poor to handle the traffic flow during morning and afternoon rush.
And I would say that unless you know enough about traffic flow management to actually do that job, you don't know that it's poor, or if it's simply as good a solution as you can get, given the flow. Maybe it's imply not possible to get any better. Easy to say it should be, hard to show how you might accomplish that.
 

MiddleGround

Well-Known Member
And I would say that unless you know enough about traffic flow management to actually do that job, you don't know that it's poor, or if it's simply as good a solution as you can get, given the flow. Maybe it's imply not possible to get any better. Easy to say it should be, hard to show how you might accomplish that.
So it's the a-typical "Maybe YOU can do a better job" reply??

I already have a job. 3 of them actually. Somewhere around this county someone else has a job that involves traffic management. I assume they are getting paid to do this job. Do you think that maybe it should be THEIR job to work on this problem? Unless, of course, you are perfectly happy with the way traffic rolls around here.

I have driven in a lot of states and countries around the world. Although some European nations are 10x worse, I would easily say that SOMD has THEE worst traffic planning I have ever driven in.
 

stgislander

Well-Known Member
So it's the a-typical "Maybe YOU can do a better job" reply??

I already have a job. 3 of them actually. Somewhere around this county someone else has a job that involves traffic management. I assume they are getting paid to do this job. Do you think that maybe it should be THEIR job to work on this problem? Unless, of course, you are perfectly happy with the way traffic rolls around here.
I didn't get anything from glhs837's reply that justified that.
 

glhs837

Power with Control
So it's the a-typical "Maybe YOU can do a better job" reply??

I already have a job. 3 of them actually. Somewhere around this county someone else has a job that involves traffic management. I assume they are getting paid to do this job. Do you think that maybe it should be THEIR job to work on this problem? Unless, of course, you are perfectly happy with the way traffic rolls around here.

I have driven in a lot of states and countries around the world. Although some European nations are 10x worse, I would easily say that SOMD has THEE worst traffic planning I have ever driven in.
Not at all, my point is that you simply cannot judge to quality of the work unless you know the details of how that work gets done in a field this complex. I've looked into it enough to know that there is far more to this sort of thing than I'll ever want to tackle to even learn if it's right or not. Easy to say traffic backs up, they must be doing a bad job. My point is that simply might not a light timing solution that can fix that, the only ways to fix it is more roadway, which is not the province of the traffic light guys, or fewer cars, which again, they cannot control. If I give you crappy tools and crooked lumber to build a thing for me, am you to blame if what you build isn't straight and true? And no, it's not the county, they have exactly zero say over RT 235. 235 is a state road, and so the SHA is the correct agency.

Happy? Nope, but that's why when I moved off of Chancellors six years back, I went south of the base. I'm quite happy with my commute. Because I controlled the variable I could.
 

glhs837

Power with Control
Here's a few bits of it. And this sort of stuff applies to one intersection. Now try and extrapolate this to the what, 5 miles where 235 is bad?

https://www.fhwa.dot.gov/publications/research/safety/04091/04.cfm#table14

If you think these folks are not working this constantly to try and better it, I think you are wrong. I also think they are doing the best they can within the parameters they have.



4.7.2 Vehicle timing—Green interval

Ideally, the length of the green display should be sufficient to serve the demand present at the start of the green phase for each movement and should be able to move groups of vehicles, or platoons, in a coordinated system. At an actuated intersection, the length of the green interval varies based on inputs received from the detectors. Minimum and maximum green times for each phase are assigned to a controller to provide a range of allowable green times. Detectors are used to measure the amount of traffic and determine the required time for each movement within the allowable range.

The minimum green time is the amount of time allocated to each phase so that vehicles in queue at the stop bar are able to start and clear the intersection. The minimum initial green time is established by determining the time needed to clear the vehicles located between the stop bar and the detector nearest the stop bar. Where presence detection is installed at the stop bar, a minimum interval may be set to a value that is less than 1.0 s.

Consider an intersection with the following properties: average vehicle spacing is 7.5 m (25 ft) per vehicle, initial start-up time is 2 s, and vehicle headway is 2 s per vehicle. For an approach with a detector located 30 m (100 ft) from the stop bar, the minimum green time is 2 + (30 m/7.5 m x 2) = 2 + (100 ft/25 ft x 2) = 10 s.

The maximum green time is the maximum limit to which the green time can be extended for a phase in the presence of a call from a conflicting phase. The maximum green time begins when a call is placed on a conflicting phase. The phase is allowed to "max-out" if the maximum green time is reached even if actuations have been received that would typically extend the phase.

4.7.4 Vehicle timing—Vehicle Clearance

The vehicle clearance interval consists of the yellow change and red clearance intervals. The recommended practice for computing the vehicle clearance interval is the ITE formula (reference 56, equation 11-4), given in equation 2 (to use with metric inputs, use 1 m = 0.3048 ft):


Change period equals perception-reaction time of the motorist plus the quotient of the speed of the approaching vehicle in feet per second divided by the sum of 2 times the comfortable deceleration rate of the vehicle in feet per second squared plus 64.4 times the grade of the intersection approach (percent) (positive for upgrade, negative for downgrade), plus the quotient of the sum of the width of the intersection from curb to curb in feet and the length of the vehicle in feet, divided by the speed of the approaching vehicle in feet per second. (U.S. Customary)

(2)





where:
CP = change period (s)
t = perception-reaction time of the motorist (s); typically 1
V = speed of the approaching vehicle (ft/s)
a = comfortable deceleration rate of the vehicle (ft/s2); typically 10 ft/s2
W = width of the intersection, curb to curb (ft)
L = length of vehicle (ft); typically 20 ft
g = grade of the intersection approach (%); positive for upgrade, negative for downgrade

For change periods longer than 5 s, a red clearance interval is typically used. Some agencies use the value of the third term as a red clearance interval. The MUTCD does not require specific yellow or red intervals but provides guidance that the yellow change interval should be approximately 3 s to 6 s and that the red clearance interval should not exceed 6 s (section 4D.10).(1) Note that because high-volume signalized intersections tend to be large and frequently on higher speed facilities, their clearance intervals are typically on the high end of the range. These longer clearance intervals increase loss time at the intersection and thus reduce capacity.

The topic of yellow and red clearance intervals has been much debated in the traffic engineering profession. At some locations, the yellow clearance interval is either too short or set improperly due to changes in posted speed limits or 85th-percentile speeds. This is a common problem and frequently causes drivers to brake hard or to run through the intersection during the red phase. Because not all States follow the same law with regard to what is defined as "being in the intersection on the red phase," local practice for defining the yellow interval varies considerably. For this reason, red light photo enforcement should not be used during the period of red clearance required by the ITE formula.

Current thought is that longer clearance intervals will cause drivers to enter the intersection later and will breed disrespect for the traffic signal. Wortman and Fox conducted a study that showed that the time of entry of vehicles into the intersection increased due to a longer yellow interval.(59) Additional research is needed to examine the effect of lengthening the yellow interval on driver behavior.
 

MiddleGround

Well-Known Member
Not at all, my point is that you simply cannot judge to quality of the work unless you know the details of how that work gets done in a field this complex. I've looked into it enough to know that there is far more to this sort of thing than I'll ever want to tackle to even learn if it's right or not. Easy to say traffic backs up, they must be doing a bad job. My point is that simply might not a light timing solution that can fix that, the only ways to fix it is more roadway, which is not the province of the traffic light guys, or fewer cars, which again, they cannot control. If I give you crappy tools and crooked lumber to build a thing for me, am you to blame if what you build isn't straight and true? And no, it's not the county, they have exactly zero say over RT 235. 235 is a state road, and so the SHA is the correct agency.

Happy? Nope, but that's why when I moved off of Chancellors six years back, I went south of the base. I'm quite happy with my commute. Because I controlled the variable I could.
And, my counterpoint to all of this is that for all of the people who are involved with this, being paid to work on this, and supposedly coming up with solutions to these problems; your big solution is "well... just move then?"

Really??!
 

edreedisgod20

New Member
Too many lights, too many cars, too many people not paying attention and/or people slow to move with the flow of traffic (a big problem, such as the old lady in the Volt who drives in the fast lane between 4-430 and who is so slow to accelerate you can fit about 8 cars between her and the one in front of her) when the lights turn or are green, emergency vehicles and crosswalks that screw up the timing for several cycles, too many bad/inconsiderate drivers who cut in to the slightest opening causing people to brake and slow things down, too many entrances/exits to shopping centers. The planning of the strip is/was a disaster and anything the engineers figure up at this point is just a bandaid.

They need a bypass or a 4th lane and neither of those things are likely to happen anytime ever. Maybe the side road opening at some point will alleviate some traffic but probably not enough to make a meaningful improvement.
 

glhs837

Power with Control
And, my counterpoint to all of this is that for all of the people who are involved with this, being paid to work on this, and supposedly coming up with solutions to these problems; your big solution is "well... just move then?"

Really??!
Yep, I live in this place called reality, where our transportation needs take a back seat to other areas. We cant even get a bridge replaced, let alone another couple lanes for 235. So yes, when I had the chance, I moved six years ago. My other big solutions require a Republican majority in MDs legislature. I'll keep voting against Dems, but damned if I'll sit in traffic every day for the last six and the next 20 years while I wait for that to come to pass. You can complain about the lights not alleviating the problem, but dont expect that to accomplish anything. My point to you was simply that I think it's simplistic to assume there some possible mitigation through manipulating the signal timing. It's not that simple, and there might not a possible solution there.

I think that fixing a lot of our traffic problems would be mitigated by actually training drivers, and then actually holding them accountable for poor driving. But we both know that's not gonna happen. So I dodge the idiots and trained my kids the same way, and preach the Gospel of Aware Driving to whomever will listen.
 

BernieP

Resident PIA
And I would say that unless you know enough about traffic flow management to actually do that job, you don't know that it's poor, or if it's simply as good a solution as you can get, given the flow. Maybe it's imply not possible to get any better. Easy to say it should be, hard to show how you might accomplish that.
I think I've said it, they can't time the lights any better because there are just so close - particularly from 4 to 237. You can almost throw a stone from one to the other.
The problem is the design on 235, what was and was not done to make it a commuter friendly route.
Numerous lights, often a quarter mile or less. Some timed, some tripped by traffic on the side street (Walmart).
Other entrance and exits
A need to make U-turns - believe it or not, people making a U-turn are even slower than people making a left.
Compound it with people who don't seem to grasp basic traffic laws and move at their own pace and you have a mash up of problems.

Just because it was always one road in and the same road out didn't mean it should stay that way. Let's be honest, the volume of traffic at certain times of the morning and evening is the problem.
Blame much of that on the base
But then you mix in school traffic
Commercial traffic (someone has to supply all those retail outlets) and last but not least, shoppers.
 

BernieP

Resident PIA
And, my counterpoint to all of this is that for all of the people who are involved with this, being paid to work on this, and supposedly coming up with solutions to these problems; your big solution is "well... just move then?"

Really??!
Don't rush to blame the professionals, well maybe the career politicians, but not those tasked with designing the roads.
They don't get to make choices , that's dictated by politics. Politicians may not put pen to paper but they choose the location, and they control the money.
235 can be seen as the product of the Great Glenndening. SMART Growth. Where you don't build something until their is chaos because to provide infrastructure in advance is to invite growth.
All the flaw of 235 can be set at the feet of him and the other politicians that had a hand in policy.
 
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