Traffic Signals

[Arlington]

Two thoughts on traffic signals:

Powderhouse Circle is eliminating all signals and letting the traffic circle and flex post calming do its work, even for pedestrians. I think this is good, (my wife got a ticket at the old signal from Phouse Blvd which was always confusing if you were accustomed to reading traffic circles)

 

[Arlington]

Thought 2: why is it ever a good thing to have more signals than traffic lanes?

maybe for visibility and redundancy above a single lane on a curve, have two signals?

But on Pleasant Street @ Mass Ave in Arlington there are three lanes: left turn, right turn and straight—yet there are four signals (two above the straight lane). How is this good?

Mostly I see people who want to go straight lining up on left or right (probably assuming that a turn lane will be added even “lefter” or righter.—which there won’t be.

 

[HelloBostonHi]

Thought 2: why is it ever a good thing to have more signals than traffic lanes?

maybe for visibility and redundancy above a single lane on a curve, have two signals?

But on Pleasant Street @ Mass Ave in Arlington there are three lanes: left turn, right turn and straight—yet there are four signals (two above the straight lane). How is this good?

Mostly I see people who want to go straight lining up on left or right (probably assuming that a turn lane will be added even “lefter” or righter.—which there won’t be.

Very simple answer actually! The MUTCD (Manual on Uniform Traffic Control Devices) requires that all approaches have two signals for the primary movement for redundancy, regardless of number of lanes. While the MUTCD is not law, most traffic engineers treat it as such. It made more sense in the era of incandescent signals, total failure in LED signal heads is much more rare.

 

[North Shore]

Very simple answer actually! The MUTCD (Manual on Uniform Traffic Control Devices) requires that all approaches have two signals for the primary movement for redundancy, regardless of number of lanes. While the MUTCD is not law, most traffic engineers treat it as such. It made more sense in the era of incandescent signals, total failure in LED signal heads is much more rare.
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The MUTCD is the governing guidance for signal design in this country, save for state amendments. Not adhering to the MUTCD leaves a designer completely liable for anything that might happen as a result of the signal design.

Furthermore, the use of two signal heads to serves as a de-facto designation for the primary movement through a signalized intersection.

 

[jass]

While the MUTCD does require two, most states do a far side and near side signal for the redundancy. Putting them side by side is pretty dumb. Theres a mediuma cross the street where they could have put the second signal, or they could have combined it with the turn signal that is posted on the far side.

 

[sneijder]

Two thoughts on traffic signals:

Powderhouse Circle is eliminating all signals and letting the traffic circle and flex post calming do its work, even for pedestrians. I think this is good, (my wife got a ticket at the old signal from Phouse Blvd which was always confusing if you were accustomed to reading traffic circles)

While we're on this topic, it'd be great to see the city use more raised intersections/brick intersections where cars are forced to slow down and yield, and eliminate traffic signals entirely. This is feasible in areas where car traffic is low enough and speeds are reduced. With the build-out of biking in cambridge I can think of a few intersections that are a good candidate for this (Sidney St Extension & Main st, Kirkland St & Quincy St, Everett St and Oxford St).

 

[RandomWalk]

Somerville, in particular, seems to have an institutional bias against permanent traffic calming measures. They do a lot of painted intersections and crosswalks, but they don’t follow-up with real curbs and raised crosswalks. They should be using the paint as an preview of calming changes coming soon, but instead drivers learn to ignore them.

I have some hope for things changing with the Spring Hill sewer separation project. The street scape improvements include a surprising number of raised crosswalks.

 

[stefal]

Somerville, in particular, seems to have an institutional bias against permanent traffic calming measures. They do a lot of painted intersections and crosswalks, but they don’t follow-up with real curbs and raised crosswalks. They should be using the paint as an preview of calming changes coming soon, but instead drivers learn to ignore them.

I have some hope for things changing with the Spring Hill sewer separation project. The street scape improvements include a surprising number of raised crosswalks.

They have been doing some nice work on College Ave. It's pretty much all cleaned up now; there's a raised crosswalk at the library, much narrower lanes throughout, an additional bike lane the entire length at the expense of parking on one side in spots, an island bus stop, and 2 pedestrian refuge islands. I think there are a few more streets throughout Somerville planned with this level of reconstruction, just seems to take a while (especially with the Bus Network Redesign now under consideration, I'm sure...)

 

[greenlinetobrooklyn]

Somerville, in particular, seems to have an institutional bias against permanent traffic calming measures. They do a lot of painted intersections and crosswalks, but they don’t follow-up with real curbs and raised crosswalks. They should be using the paint as an preview of calming changes coming soon, but instead drivers learn to ignore them.

I have some hope for things changing with the Spring Hill sewer separation project. The street scape improvements include a surprising number of raised crosswalks.

Somerville is also in the process of finishing the three way intersection of Broadway, Winchester and Albion Sts, making a large permanent curb bump out at Albion and Broadway and pedestrian refuge on Broadway

 

[reno]

An excellent video on You Tube on why people run red lights and how to fix it, and it doesn't involve red light cameras. Video by "Road Guy Rob"

 

[BeyondRevenue]

An excellent video on You Tube on why people run red lights and how to fix it, and it doesn't involve red light cameras. Video by "Road Guy Rob"

RGR is one of my faves - the Highway rule-Fu is strong with him. Another solid effort from him and a good share by you, reno.
I do wonder how he would treat our streets (very small and pre-car organic), as opposed to those manufactured in the last 50 years - like most of his western US examples. Whenever I have to drive in CA and NV, I think of how Bostonians treat 1 lane like 3 and they treat 3 lanes like 1. We're different animals altogether. Grade on a scale that includes road oddities and New England Drivers are massively skilled compared to the Fisher-Price level drivers out there. They don't understand New England roads so they blame us instead of our infrastructure.
There is one glaring exception to where we are awful: The somehow normalized left-hand turn sprint AGAINST ONCOMING TRAFFIC to beat traffic going straight. This car-jousting crap is almost entirely a Masshole thing. I've never seen this anywhere else. I would put up signs, signals, cameras, attack dragons -- anything to get this crap to stop.

 

[JeffDowntown]

The somehow normalized left-hand turn sprint AGAINST ONCOMING TRAFFIC to beat traffic going straight. This car-jousting crap is almost entirely a Masshole thing. I've never seen this anywhere else. I would put up signs, signals, cameras, attack dragons -- anything to get this crap to stop.

And the counterpoint to this madness is awful as well. Outside of Masshole-land you are trained to make a left turn (at a no left arrow intersection) on the yellow light, assuming the oncoming traffic will be stopping on the yellow. Here you get 5 cars rushing through on orange to bright red. No left turn opportunity.

 

[RandomWalk]

Left turns usually end up blocking the box or clogging the intersection because folks don’t yield. I’m not sure I would say it’s exclusive to MA, but we don’t have as many of the add-a-lane-because-why-not intersections.

The turns from Broadway in Teele Square are a prime example. If anyone wants to turn to Clarendon, it will block up the flow for folks continuing west on Broadway. The eastbound drivers on Broadway will block up the intersection because they want that extra car length when the light turns. The left turn on to Curtis will block up the remainder of the cycle, because yields lead to honking. If you have both turns to Curtis and to Clarendon happening in one phase, it’s full Keystone Kops.

 

[North Shore]

While we're on this topic, it'd be great to see the city use more raised intersections/brick intersections where cars are forced to slow down and yield, and eliminate traffic signals entirely. This is feasible in areas where car traffic is low enough and speeds are reduced. With the build-out of biking in cambridge I can think of a few intersections that are a good candidate for this (Sidney St Extension & Main st, Kirkland St & Quincy St, Everett St and Oxford St).

As someone who once worked as a staff Engineer (and plow) for a town northwest of Boston, the counterpoint to this is the need for additional drainage structures to drain the water that gets trapped by the raised impediments and that these are hell for snowplow operations in the winter.

 

[ceo]

What's worse is trying to turn left from Alewife Brook Parkway onto Broadway, in either direction, where there is inexplicably no exclusive phase. If you don't floor it the second the light turns green you're just going to sit there for the entire cycle.