Memo - Speed Limit DiscussionPublic Works Department
Memorandum
To: Honorable Mayor and Members of the City Council
Copy: Rick Getschow, City Manager 4�f�
From: Steven J. Stadler, Public Works Director
Date: October 21, 2009
Subject: Speed Limit Discussion
It is not uncommon for residents to request a lower speed limit on local streets or to
generally question the current 30 mph statutory speed limit for urban districts. People
are driving faster and certainly the number of cars on the road increases each year -
this is true on the freeways and even in the residential areas. Accordingly, the local
government issue of traffic speed and volume comes up on a more frequent basis. In
most instances, in order to change a speed limit an engineering and traffic investigation
must be done and, generally, Mn /DOT sets the speed limit near the 85th percentile
speed (the speed where 85% of vehicles are traveling at or slower).
However, current MN State Law does allow for some local authority to reduce speed
limits from the 30 MPH statutory speed limit, as follows:
• On a segment of road up to a half -mile long that is classified as a local street, a
local road authority may reduce the speed limit to 25 MPH.
• In school zones, a local road authority may prescribe a lower limit not less than
15 MPH. School zones are segments of road that abut school grounds where a
school crossing is established.
• Subject to certain conditions, park roads or roads with bicycle lanes may be set
below 30 MPH.
In 2008, the State Legislature required Mn /DOT to conduct a speed limit study. They
had last formally studied the local road speed limit topic in 1993 -1994.
The 2008 study included a Task Force process comprised of Mn /DOT and local
municipal representatives as well as research and interviews with local engineering and
law enforcement personnel. The resulting Mn /DOT report entitled: " Study and Report
on Speed Limits covered several topics including: "Is 30 MPH in urban districts
appropriate?" and "Are there locations where 25 MPH is appropriate ?"
The study includes the following Mn /DOT recommendations:
Do not change the basic Urban District speed limit of 30 MPH.
The residential roadway definition be changed to mean a street that is less than
one -half mile in length and is functionally classified as a local street. They
recommended that the phrase, "or portion of a street" be deleted.
The reasons for the recommendation of no change to the 30 MPH statutory speed limit
are as follows:
• Analysis of pedestrian crash data between Minnesota, Wisconsin and Iowa
yielded inconclusive results as to the safety benefits of a 25 MPH (Iowa and
Wisconsin) versus 30 MPH speed limit. Plus, pedestrian crashes tend to occur
along or crossing higher - volume collector or arterial streets, not in residential
areas.
The current funding environment precludes establishing proper enforcement of
a 25 MPH speed limit. Thus, there would be an even larger disparity in actual
travel speed from the posted speed limit. As we know, posting signs does not
change driver behavior.
The reasons for the recommended change to the residential roadway definition are:
The recommendation was based on the understanding that the original intent
of this provision was to apply to entire short roads, not to segments of
continuous roads. Plus, cities could still request a speed study to support
lowering the speed limit to 25 MPH on longer roadways.
If a city implements a 25 MPH speed limit on a residential roadway or portion thereof,
they are required to install speed limit signs at the beginning and end of the roadway.
School zone speed limits
Cities may establish school zone speed limits on roads under their jurisdiction. Prior to
establishing a school zone speed limit, a traffic investigation must be done. The
investigation must consider: the school route plan, hazard identification and education.
See attached information sheet.
Recently there has been concern regarding the safety of children around the St. John
Elementary school at the corner of Interlachen Rd. and Boyce St. In looking at this
situation along Boyce Street, it appears that additional crossing signs and on- street
parking restrictions could help improve safety. Staff recommends that this area be
investigated as a possible school zone to determine if posting school zone reduced
speed limit signs, 20 MPH, and /or other measures could improve child safety. St John
school has an enrollment of 155 pre -K thru 6th grade students. School hours are 9:00
am - 3:30 pm.
Staff does not recommend that we post 25 MPH speed limit signs on any of our
residential roadways. As previously mentioned, a pedestrian safety improvement can
not be substantiated, it would be very difficult to enforce and the signs would not result
in slower speeds. Countless studies have confirmed that reasonable drivers travel at
speeds commensurate with the roadway conditions, not based on what the maximum
speed limit is, i.e. 30 MPH in urban districts.
F MN Statute 169.14
Speed laws are created for the protection of
the public and the curbing of unreasonable
behavior. To effectively enforce a law, the
public must believe that the law is
reasonable. Minnesota's speed regulations are based on the
same Basic Speed Law that is used in all 50 states: "No
person shall drive a vehicle on a highway at a speed greater
than is reasonable and prudent under the conditions ".
Statutory limits are based on the concept that uniform
categories of highways can operate safely at certain preset
maximum speeds under ideal conditions. Whether the speed
limit is posted or unposted, drivers are required to reduce
speed below these values for poor weather conditions, curves
or hills and potential hazards such as pedestrians. Drivers
must also reduce speed when approaching or passing
emergency vehicles with emergency lights flashing.
These are the most common statutory speeds:
i 10 mph in alleys
1 30 mph on streets in urban districts
70 mph on rural interstate highways
65 mph on urban interstate highways
65 mph on expressways
55 mph on other roads
Whenever these statutory speed limits are not the correct
value for a specific highway, the commissioner of
transportation authorizes the posting of other regulatory
speed limits.
Interstates are high design multi -lane divided highways
that have controlled access interchanges such as cloverleafs
or diamond shaped interchanges. Through traffic on the
interstate never has to stop or yield. Examples: 1 -94 or 1 -35
all Expressways are multi -lane divided highways but they
® have entries and intersections, sometimes controlled by
traffic signals. Some interchanges may exist but they are
not the rule. Examples: Highway 10 or Highway 52
The commissioner of transportation sets regulatory speed
limits on state and local roads based on a thorough
engineering and traffic investigation.
These factors are considered:
road type and condition
location and type of access points (intersections,
entrances, etc.)
sufficient length of roadway (1/4 mile minimum)
existing traffic control devices (signs, signals, etc.)
crash history
traffic volume
sight distances (curve, hill, etc.)
test drive results
.,..speed study
The most important part of the traffic investigation is the
speed study. When choosing a speed, drivers take many
roadway environment factors into consideration. Therefore,
the speed that the majority of people consider prudent is an
important value. Data is collected by performing radar
checks at selected locations on the roadway under ideal
driving conditions. A technical analysis is done on the results
to determine the 85th percentile. This is the value indicating
the speed at which most (85 %) drivers are traveling under.
Experience has shown that a posted speed limit near this
value is the maximum safe and reasonable speed. Studies
have shown that traveling much faster or slower than this
value can increase your chance of being in a crash.
Engineering judgement is an important tool. The traffic
investigator must use knowledge of nationally accepted
principles combined with experience to assign the safe speed.
IyNESry,
August 2002
$J r Minnesota Department of Transportation
_Office of Traffic Engineering &
Intelligent Transportation Systems
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REGULATORY SPEED LIMIT SIGN
SPEED This black and white sign shows the maximum speed
tIM1T that a motorist may travel under ideal conditions. It
50 can be a statutory value or else it must be authorized
by the commissioner of transportation.
ADVISORY SPEED SIGN
This black and yellow speed sign is used to advise
motorists of a comfortable speed to navigate certain
situations. It is used with a warning sign. For
instance, when traveling on a winding road, the curve
2 5
MPH warning sign would be used with an advisory speed
M , H sign. This sign may be posted by the local road
authority on local roads.
SPEED LIMITS IN SCHOOL ZONES
sceaw� Local authorities may establish school speed limits on
local streets, within a school zone, upon the basis of
SPEED an engineering and traffic investigation as prescribed
LIMIT by the commissioner of transportation. This
20 regulatory speed limit is in effect whenever children
are present, such as before and after school or during
recess. The school plate is black and yellow and the
other signs are black and white. Optional flourescent
yellow green may be used for the school plate.
SPEED LIMITS IN WORK ZONES
Advisory speed limits are used to identify safe speeds
f , for specific conditions within a work zone. These
black and orange signs are always used with warning
signs. The local road authority can post these plates in
work zones on local roads.
Work zone speed limits are short tern regulatory
speed limits that are established for worker safety due
to traffic in adjacent lanes. These speed limits range
sPEeD from 20 mph to 40 mph on two lane -two way roads
LIMIT and up to 55 mph on divided highways. They can be
40 posted by the local road authority in active work zones
on local roads. The FINES DOUBLE plate is black
and orange and the speed limit sign is black and white.
Temporary speed limits in construction zones are
SPEED sometimes needed for long term construction projects
LIMIT or detour routes. These regulatory black and white
50 signs are used when a reduced speed is needed for
driver safety. Valid 24 hours a day, 7 days a week,
these must be authorized by the commissioner of
transportation for any roadway.
See the website: www.dot.state.mn.us /speed
for more information on "Work Zone Speed Guidelines"
Will lowering the speed limit reduce speeds?
NO. Studies show that there is little change in the speed pattern
after the posting of a speed limit. The driver is much more
influenced by the roadway conditions.
Will lowering the speed limit reduce crash frequency?
NO. Although lowering the speed limit is often seen as a
cure -all in preventing crashes, this is not the case. Crashes are
most often the result of driver inattention and driver error.
However, if a posted speed limit is unrealistically low, it creates a
greater speed variance (i.e. some drivers follow the speed limit
while most drive the reasonable speed). This speed variance can
contribute to crashes.
Why do we even have speed limits?
A uniform speed of vehicles in a traffic flow results in the
safest operation. The posted speed limits can keep the traffic
flowing smoothly provided the majority of drivers find the
speed limits reasonable. To best do this, the limits must be
consistent throughout the state. The speed limits also give the
motorist an idea of a reasonable speed to drive in an unfamiliar
location. The speed limits are used by police officials to
identify excessive speeds and curb unreasonable behavior.
If you believe that there is a safety concern or an inappropriate
speed limit posted, the person to contact depends on the type of
road.
TRUNK HIGHWAYS
For regulatory and advisory speed limits on the trunk highway
system, you may contact the district traffic engineer at your
Mn /DOT district office.
The trunk highway system includes:
'; Interstate Highways,
0 U.S. Highways and
❑ Minnesota State Highways
LOCAL STREETS AND HIGHWAYS
For these roadways, you may contact your local road authority
(county, city, or township). For advisory speed limits: The
local road authority can determine these advisory speeds and
post the plates without authorization from the commissioner of
transportation. For regulatory speed limits: The local road
authority can pass a resolution requesting an investigation by
Mn /DOT. Based upon the results, Mn/DOT may then
authorize the local road authority to post new speed limits.
The phone numbers to call for state or local assistance can be
found in the phone book under government listings. If you are
unable to find the proper phone number, you may call the
Mn /DOT Information Center at the following numbers:
1- 800 - 657 -3774 Greater Minnesota or
651- 296 -3000 Twin Cities Metro Area
J DOUBLE FINES will be imposed for violating any regulatory speed limits in work zones or
i in school zones. Fines are also double for failing to reduce speed when passing by a stopped
emergency vehicle with its lights flashing.
NOt e , S J When an EMERGENCY VEHICLE is approaching you, move to the closest shoulder
without crossing the path of the approaching emergency vehicle. You may proceed when the
emergency vehicle passes you. If you are approaching a stopped emergency vehicle with its lights flashing, immediately reduce
speed and, if it's safe to do so, move over in your lane away from the stopped emergency vehicle. Drivers should actually change
lanes if there are two or more lanes in the same direction and there are no vehicles in their path.
School Zone Speed Limits
SCHOOL ZONE SPEED LIMITS
Ensuring the safety of children on public streets near schools is
the responsibility of parents, school officials and road
authorities. Parents must provide basic training and
supervision in order to develop safe behavior and serve as role
models. School officials must support and encourage
educational safety programs and methods for walking or
biking students. Road authorities must provide a safe
environment on the street by using proven traffic control
methodologies that will minimize the crash probability.
THE LAW
Each road authority may establish school zone speed limits on
roads under their jurisdiction. In order to provide an objective,
uniform and safe environment for walking and biking students,
Minnesota law requires a traffic investigation as prescribed by
the Commissioner of Transportation prior to establishing a
school zone speed limit.
The school zone is legally defined as that section of road
which abuts the school grounds, or where there is an
established school crossing with advance school signs that
define the area. If a reduced school speed limit is warranted:
- It shall not be more than 30 MPH below the establish speed
limit
- The school speed limit shall not be lower than 15 MPH
- All signs erected must be in conformance to the Minnesota
Manual on Uniform Traffic Control Devices. Any speeding
violations of a school zone speed limit are subject to a double
fine.
SCHOOL AGE PEDESTRIAN CRASHES
While safety is emphasized near schools, pedestrian crash
experience requires a broader look. A Minnesota study
revealed that 88 percent of school age pedestrian crashes
occurred more than one block from school. Similar studies in
Idaho showed only 13 percent of school age pedestrian crashes
occurred in a school zone but 31 percent occurred on the trip to
school. Other states have confirmed similar results. The
statistics point out that location is NOT the predominant factor,
suggesting that safety education for pedestrians has the
greatest potential for improvement since they can use it at all
locations..
Further insights can be gathered from analysis of
circumstances contributing to school age crashes.
- Most crashes occurred when the child dashed from behind
parked cars
- Many crashes occur at mid -block locations
- Kindergarten through third grade pedestrians had
considerable difficulty understanding traffic control devices.
In realization of these facts it is apparent that school age child
safety is not a singular issue of speed limits. Real
improvements in safety require a comprehensive study of the
school trip and each environment must be specifically
addressed.
THE TRAFFIC INVESTIGATION
Mn/DOT developed the booklet "A Guide to Establishing Speed
Limits in School Zones" that is a comprehensive safety outlook
and is the prescribed method as required by MS 169.14. Three
distinct components are addressed -
The School Route Plan
Hazard Identification
Education.
The main objective of the School Route Plan is to establish
walking routes that minimize the number of streets crossed and to
maximize the safety of approved crossings used by children on
the entire trip to school.
Hazard Identification addresses nine issues using the school
route plan and evaluates each street for what is present as well as
what can be changed to enhance the safety of the planned routes.
A quick summary:
1) Roadway geometry- crossing narrower roads in straight
sections with good sight distance increases the safety to
pedestrians.
2) Traffic volume- low volume roads are safer to cross. High
volume roads will require adult crossing guards for maximum
safety.
3) Pedestrian volumes- number of pedestrians can determine
signal timing or necessitate additional traffic control.
4) Parking- parking should be banned in the immediate area of
any school crossing.
5) Traffic Control Devices- these should be reviewed to verify
they are operating correctly and signs are not hidden by
vegetation.
6) Sidewalks - children walking in the street is dangerous.
Continuous sidewalks that do not intermittently disappear and
force children into the road are the best.
7) Fencing - strategically placed fencing can change walking
patterns and prevent dangerous mid -block crossing. At
playgrounds, it prevents errant kick -balls from rolling into the
street and causing children to chase them from between parked
cars.
8) Crash History - crash investigation can reveal locations
where remedial measures may not be working and pedestrians
should be routed away from these areas.
9) Speed zones- if all other measures have been addressed and a
reduced speed is still required to safely navigate the school zone,
then a school zone speed limit should be considered. Trained
engineering personnel should design speed limits based on the
limiting criteria and arbitrary blanket values should be avoided.
As noted before, education is the most important. All the best
efforts of engineering and planning will be lost if the pedestrian is
unaware of the safe routes and safe practices. Children are rarely
involved in crashes while crossing properly. Education is not the
singular responsibility of one group or person, it requires a
partnership and commitment from all.
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Minnesota Manual on Uniform Traffic Control Devices
Signing for School Area Traffic Control
Prepared by the Office of Traffic Engineering and ITS
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