[Neighbors] Nob Hill seeks your support on Lead and Coal Aves.

[Jim Barrera]

A couple neighbors asked me to weigh in on this issue, so I will share what
I know.

There are some speed-actuated traffic signals in operation elsewhere in the
U.S.  One type has the signals “rest in red” on all approaches.  When the
detectors sense vehicles approaching at or under the speed limit, the
system gives that approach a green light.  If the detectors sense vehicles
approaching at above the speed limit (possibly with some leeway allowed),
it holds that approach on red until the vehicles arrive and have to stop.

Traffic engineers have learned several things about these systems:

1.  For them to be effective, there must be driver education about the
system.  Drivers must understand that their behavior (speed) is directly
affecting whether they get a green light or not.

2.  Related to #1, these systems may be effective at isolated intersections
with single-lane approaches, where the behavior/reward is obvious to the
driver.  They are not considered effective for roadways with multiple
lanes, where other vehicles will often trigger the system punishing
everyone else who was traveling at the speed limit.

3.  They are not recommended for roadways with high traffic volumes.  Other
cities have found that about 5,000 vehicles per day is the maximum traffic
where these systems work well.  Lead/Coal each move upwards of 14,000
vehicles per day.  At these higher traffic volumes, such systems triggering
extra red lights will just cause unnecessary congestion.

4.  These systems can work well at isolated intersections, but they are
inappropriate for a corridor with timed coordinated traffic signals.
Lead/Coal is a coordinated corridor with signals timed for 30 MPH.  During
peak commute periods, they move the platoons of vehicles efficiently
through the system.  A speeding vehicle in the middle of the night may be
stopped by this system, but during rush hour, just a few activations will
turn Lead/Coal into gridlock.

A second type of system is not rest-in-red, but one that operates like a
normal traffic signal alternately giving the main street and cross streets
green lights/red lights.  When the green is on the main street and it
senses a vehicle approaching at above the speed limit, the system will
change it to yellow and then red.  The system would have to detect the
speeding vehicle far enough in advance of the intersection that the safe
required yellow time can be provided and go to red before the vehicle
arrives.  On Lead/Coal, this type of operation may be effective to curtail
the excessive speeders in off-peak hours like at night when there is little
traffic.  But it would still be inappropriate to do this during coordinated
timed operation for peak traffic hours.

`jimb



On Mon, Feb 8, 2021 at 11:13 AM Melodie Eyster via Neighbors_nobhill-nm <
neighbors_nobhill-nm at mailman.swcp.com> wrote:

> Good morning, Antoinette and Gail.
>
>
>
> Nob Hill and surrounding neighborhoods need your support for the *Lead &
> Coal Safety Upgrades Capital Outlay Request, LCS Project ID 1275.*
>
>
>
> Capital Outlay Request Amount: $250k
>
> Total Project Cost: $350k
>
> Funding Secured: $100k
>
> State ICIP Project ID: 30957
>
> LCS Project ID: 1275
>
>
>
> Along with our sister associations, University Heights and Southeast
> Heights, Nob Hill Neighborhood Association has long sought an answer to the
> speeding, reckless driving, and high speed accidents on Lead & Coal Aves.
> We’ve tried virtually everything but the situation is still horrible.
>
> City Councilor Pat Davis has come up with an innovative idea to install
> speed sensitive traffic signals known as rest in red signals that only turn
> green when the approaching vehicle is traveling at or below the speed
> limit. The project is in the study and design phase.
>
> The capital outlay request of $250,000 would be combined with City funds
> of $100,000 to implement this project, save lives, and enhance quality of
> life for hundreds of families on the corridor.
>
>
>
> We urge your support and we urge any neighbor who feels the same to reach
> out as well.
>
>
>
> Kind regards,
>
>
>
> Gary Eyster
>
> President, Nob Hill Neighborhood Association
>
>
>
>
> _______________________________________________
> Neighbors_nobhill-nm mailing list
> Neighbors_nobhill-nm at mailman.swcp.com
> https://mailman.swcp.com/cgi-bin/mailman/listinfo/neighbors_nobhill-nm
> This Message Sent To: chiledoggie at gmail.com
>
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