Dear Mayor and Councilmembers,
I am writing as a Partridge Avenue resident in support of the Slow Streets
Program, and to flag a critical flaw in the data the program currently
relies on.
The 85th-percentile speed metric is the wrong tool for streets like ours,
which are intended to be entirely residential but have become popular high
speed pass throughs. Partridge is a clear illustration of why.
Most of the cars on Partridge each day belong to people who live here. We
make many slow trips down our own street — school drop-off, Trader Joes,
Burgess for soccer, daily errands. We have kids in our cars. We know the
kids walking to and from school. We drive carefully. That is
*neighborhood* traffic
— not the danger Slow Streets is trying to correct.
The problem is that we make a *lot* of those trips, and, because most lots
on Partridge are double lots, our residential density is more than double
that of a comparable length street. The sheer volume of safe, local trips
statistically drowns out the number of drivers who are cutting through
Allied Arts during the morning and evening rush — drivers who dont live
here, dont know the children on the street, and are causing the greatest
actual risk.
The 85th-percentile metric, by design, looks at the bulk of vehicles and
discards the tail. On a street where the bulk of vehicles are responsible
neighbors and the tail is anonymous cut-through speeders, the approach is
precisely upside down. It tells the City our street is fine because our own
slow trips outnumber the dangerous ones. It filters out the very vehicles
we need the program to address.
Top speeds recorded on streets like Partridge run into the 40s and 50s.
Those are not residents. Those are exactly the drivers we need to identify
and remediate. The current scoring framework cannot see them, nor the fact
that these drivers also do not come to full stops at signs and cut blind
corners in a particularly dangerous way to oncoming traffic.
This matters because Partridge concentrates vulnerable road users. The
double-lot density doubles the number of children walking to and from
school each day. Partridge is also home to a senior living facility,
putting more vulnerable users on the street at the same time as peak rush
traffic. We have already had an injury collision on Partridge after years
of resident requests for safety help. The City was on notice. The collision
happened anyway.
I also support the Allied Arts gateway and network treatment plan being
requested for College Avenue, and would support a coordinated pilot that
includes Partridge. But the immediate, generalizable fix the program needs
from Council is in the data: scoring criteria that surface dangerous
outliers rather than filter them out.
I am asking Council to:
1. Approve the Slow Streets Program tonight.
2. Direct staff to use accurate and appropriate speed measurements that
capture the vehicles causing the greatest risk of serious injury or
fatality — not a metric that, by design, excludes them. Or, allow access to
the program through other reasonable demonstrations of need where the speed
data is known to be unreliable.
3. Direct staff to launch a 90-day, low-cost, quick-build pilot of the
Allied Arts network treatment plan, using the same SFMTA-validated
toolkit (gateway signs, flexible delineators, visual narrowing) that has
sustained a 36% collision reduction on Sanchez Street in San Francisco for
over five years.
The current system only benefits non-residents. I urge you now to make
simple choices that protect your constiuents. Please vote to approve a
strengthened Item H-2 that fixes the data flaw and leverages low-cost,
proven intervention systems.
Thank you,
Bjorn Carey
