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Traffic Calming - tabled intersections

LTrain

Cyburbian
Messages
46
Points
2
Do tabled intersections actually slow traffic ? We are considering them on a mixed use street that is getting some street improvements over the next few years. Thoughts ?
 

Dan

Dear Leader
Staff member
Moderator
Messages
18,808
Points
69
I can't quote any studies, but in my opinion, vertical traffic calming really isn't that effective. It may slow traffic for a little bit, but drivers will speed up after to make up for lost time. I do know that cyclists hate vertical calming, and it . I think smaller curb radii, bumpouts, textured pavement, or a mini-roundabout would be just as effective. Psychological traffic calming (on-street parking, street trees, etc.) also works.

That being said, the municipality where I work, and the core city in the region, are both true believers in vertical traffic calming. Speed tables are very popular where I live. I was "persuaded" to add them into a FBC I'm writing, where earlier drafts prohibited all vertical calming. There's a lot of traffic congestion, bike traffic, and very rough pavement, though, so I don't think tables do much more to slow down traffic.
 

luckless pedestrian

Super Moderator
Staff member
Moderator
Messages
12,646
Points
54
I agree with @Dan - narrowing streets, separating out lanes for bicycles, boulevard-like layouts, street trees, and mini round-abouts all are much more effective than any kind of speed bump or tabling -
 

Gedunker

Moderating
Staff member
Moderator
Messages
11,551
Points
42
I wouldn't underestimate the amount of noise speed tables generate, either. The "thump - thump" of mounting, demounting, and the sound of acceleration as drivers pull away (usually trying to make up for lost time). In a residential area, that noise may well be a deal-breaker. Put me down with Dan's suggestions.
 

southern_yank

Cyburbian
Messages
144
Points
6
Like the other members mentioned, horizontal traffic calming is the best option. It tends to slow down traffic continuously instead of in short spurts. Tabled (or raised) intersections work best as an urban design component linking two pedestrian paths or paseos together. For example, think of the Fremont Ave. Experience in Las Vegas. Connecting those pedestrian corridors with raised intersections between each block would be an ideal use of tabled intersections.
 

Doohickie

Cyburbian
Messages
3,087
Points
44
How so? I thought the whole point of a tabled intersection is that it raises it up to the level of the pedestrian curb level.
 

Bridie1962

Member
Messages
18
Points
1
There is a cross slope. According to US Access Board
"Cross slope is the slope perpendicular to the direction of pedestrian travel (see R105.5). Cross slope impedes travel by pedestrians who use wheeled mobility devices since energy must be expended to counteract the perpendicular force of the cross slope. Cross slope makes it more difficult for pedestrians who use wheelchairs to travel on uphill slopes and to maintain balance and control on downhill slopes. Cross slope also negatively affects pedestrians who use braces, lower limb prostheses, crutches, or walkers, as well as pedestrians who have gait, balance, or stamina impairments. The proposed guidelines specify a maximum cross slope of 2 percent for pedestrian access routes, including pedestrian access routes within sidewalks and pedestrian street crossings with yield or stop control where vehicles slow or stop before proceeding through the intersection (see R204.3 and R302.6)."

The importance of careful design and oversight.
 

Doohickie

Cyburbian
Messages
3,087
Points
44
But....

Every road has that for drainage, and non-tabled intersections also have the ramps that go from the gutter level to the curb level.
 
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