BILL ANALYSIS
SENATE TRANSPORTATION & HOUSING COMMITTEE BILL NO: sb 570
SENATOR ALAN LOWENTHAL, CHAIRMAN AUTHOR: maldonado
VERSION: 2/27/09
Analysis by: Jennifer Gress FISCAL: yes
Hearing date: March 31, 2009
SUBJECT:
Prima facie speed limits
DESCRIPTION:
This bill establishes a prima facie speed limit of 40 miles per
hour (mph) for any roadway where the residential density is
eight residential units or more fronting the street.
ANALYSIS:
Existing law establishes a maximum speed limit of 65 mph for
most highways and 55 mph for two-lane, undivided highways.
Additionally, existing law establishes what are referred to as
"prima facie" speed limits for specified circumstances and types
of roadways, as follows:
15 mph when traversing a railway grade crossing, when crossing
an intersection of highway if view is unclear or obstructed,
or when driving in an alley.
25 mph on any highway other than a state highway that is in
any business or residence district, in a school zone, or in an
area with facilities primarily used by senior citizens.
A residence district is defined as a portion of highway and the
property contiguous thereto upon which there are 13 or more
separate residential or business structures on contiguous
property fronting one side of the highway or 16 or more such
structures on both sides within a -mile distance.
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Existing law permits the California Department of Transportation
(Caltrans) and local agencies to change these speed limits if
done so in accordance with an engineering and traffic survey
(ETS). An ETS measures prevailing vehicular speeds and
safety-related factors including accident records and highway,
traffic, and roadside conditions not readily apparent to the
driver. Local authorities may also consider such factors as
pedestrian and bicyclist safety and residential density.
A speed limit is generally set at or near the 85th percentile of
the prevailing speed (i.e., the speed which is exceeded by 15
percent of motorists) as measured by an ETS, unless
safety-related factors suggest a lower speed limit is
appropriate. In cases where the 85th percentile speed is not an
increment of 5 mph, a jurisdiction rounds the speed limit to the
closest 5 mph increment. Thus, if the survey shows an 85th
percentile speed of 34 mph, the speed limit will be set at 35
mph. The California Manual on Uniform Traffic Control Devices
(MUTCD) specifies that a jurisdiction may lower that speed limit
by 5 mph (i.e., to 30 mph in the example) if safety-related
factors suggest that lower speed is warranted. The jurisdiction
cannot, however, lower the speed limit by more than 5 mph,
regardless of additional safety factors.
This bill establishes a new prima facie speed limit of 40 mph on
any street or road, other than a state highway, where the
residential density consists of eight residential units or more
fronting the street over a distance of mile.
COMMENTS:
1.Purpose . The sponsor, the San Luis Obispo County Board of
Supervisors, would like to lower the speed limits within rural
residential subdivisions. Rural residential subdivisions are
composed of one acre lots and as a result do not have the
residential density to establish a 25 mph prima facie speed
limit. The County has conducted an ETS for many of these
roads and the result is that the majority of these rural
residential streets would be required to be posted at 45 mph.
The streets have pedestrian, equestrian, and cyclists as
expected in a residential area and so the 45 mph speed limit
is not desirable to the County. Moreover, the sponsor points
out that many of these streets have lower design speeds than
the speed limit established through an ETS. The ultimate
SB 570 (MALDONADO) Page 3
objective of the bill, according to the author, is to improve
the safety of these roads by establishing lower speed limits.
2.Need for the bill ? The intent of this bill is to reduce the
speeds at which drivers on these roads travel, thereby
reducing collisions. It is not clear, though, the extent to
which speeding is in fact a problem in San Luis Obispo County,
nor is it clear that this bill will help the County address
that issue.
The 85th percentile is chosen as the standard for establishing
speed limits with the assumption that most drivers drive at a
speed that they feel is safe for the conditions. Posting a
lower speed limit is unlikely to change the extent to which
drivers feel safe driving at the prevailing speed because the
roadway and driving conditions remain unchanged.
The county provided data for 20 rural roads that fall under
the classification established by the bill. Of these, 18
roads have a posted speed limit and two do not. Fifteen of
these 18 (83.33 percent) currently have a posted speed limit
of 40 mph or less. Furthermore, if these 20 road segments
were posted in accordance with the ETS's that the county
conducted, only six speed limits would change under this bill
once safety-related factors were considered, and five of those
six would be reduced by just 5 mph. These findings raise
questions regarding the need for the bill.
To assess the potential impact of this measure on collision
rates, staff examined whether the speed limit would change on
those roads that have collision rates that exceed the
county-wide average. Six of the 20 road segments have
collision rates above the county average of 2.48 collisions
per million vehicle miles traveled. Of these six, two speed
limits would be lowered under this bill.
This bill seeks to circumvent the existing process for
establishing speed limits. The nature of the speeding problem
is unclear, as is whether the bill will result in meaningful
changes to the posted speed limits or whether lower speed
limits will in fact slow drivers down.
3.Enforceability . The sponsor argues that many of the posted
speed limits are not enforceable because the speed limits were
not set in accordance with a valid ETS. Furthermore, the
ETS's conducted for these road segments in many cases resulted
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in higher speed limits than those that are posted. Posted
speed limits that were not established with an ETS are in fact
enforceable, just not through the use of radar, provided that
the law enforcement officer demonstrates that the driver was
driving at a speed unsafe for conditions. Additionally,
existing law allows radar to be used to provide evidence of
unsafe speed on local streets and roads, even if the speed
limit is not justified by an ETS.
4.Applicability of standard statewide ? The standards
established in the bill - 40 mph on a road with eight or more
residential or business structures within a -mile distance -
were chosen based on circumstances specific to San Luis Obispo
County. While they may be valid for certain areas in that
county, it is unclear that they are valid in other areas of
the state. Moreover, no evidence has been submitted to
suggest that 40 mph is an appropriate speed for an area with
eight or more structures within a mile. The committee may
wish to consider whether it is prudent to establish a new
prima facie speed limit without some evidence that it is an
appropriate speed for these types of roads.
5.Changes to the ETS procedure forthcoming . Since 2004, the
procedure for determining the 85th percentile has involved
rounding to the closest 5 mph increment, which in some cases
requires an agency to round up to the next highest increment.
This has caused concern that some speed limits were being set
too high and that as a result agencies were lowering the speed
limit 5 mph due to safety factors, regardless of whether those
safety factors existed. Prompted by SB 848 (Corbett) in 2007,
which did not pass the Legislature, the California Traffic
Control Devices Committee, a state administrative body, has
considered changing the procedure to allow agencies to
establish a speed limit within 5 mph of the 85th percentile,
thereby permitting agencies to choose whether to round up or
down to a 5 mph increment. (If San Luis Obispo County chose
to round in a more conservative manner, then only 4 of the 20
speed limits on the roads for which the County provided data
would change under the bill.)
6.Technical amendments . The bill establishes a new road
designation for a "residential suburban road." This term,
defined as a street or roadway were the residential density
consists of eight residential units fronting the street over a
-mile distance, conflicts with an existing definition of
"residence district." To clarify that the roads addressed by
SB 570 (MALDONADO) Page 5
this bill constitute a separate classification reflecting less
density than a residence district, the author or committee may
wish to consider the following two amendments.
a. Page 3, line 24, after "eight" insert "to 12"
b. Under "words and phrases defined" in Division 1 of the
Vehicle Code, add a definition for "residential suburban
road," defining it as "any street or roadway and any
highway, other than a state highway, where the residential
density consists of 8 to 12 residential units or more
fronting the street, roadway, or highway over a distance of
one-quarter mile."
POSITIONS: (Communicated to the Committee before noon on
Wednesday,
March 25, 2009)
SUPPORT: County of San Luis Obispo (sponsor)
OPPOSED: AAA of Northern
California
Automobile Clubs of Southern California