HomeMy WebLinkAboutMNDOT Hwy 36 Early Warning Flashing Lights f y�o�„NNESO,�y
Minnesota Department of Transportation
�nepd Metropolitan Division
Waters Edge
1500 West County Road 62
Roseville, MN 55113
September 24, 2004
Mr. Eric Johnson, City Administrator
Mr. Lindy Swanson, Chief of Police
City of Oak Park Heights, MN
14168 Oak Park Blvd N, Box 2007
Oak Park Heights, MN 55082
RE: Crash Rates and Advance Warning Flashers on TH 36, in OPH/Stillwater
Dear Mr. Johnson and Mr. Swanson,
MnDOT Metro Traffic Engineering was recently contacted by Department of Public
Safety personnel, and your letter of August 9, 2004 was sent over. The collection and
storage of crash records is officially the responsibility of DPS. MnDOT has access to
these DPS records. The specific analysis that you are requesting of crash records and
rates is typically performed by MnDOT. Therefore I have gone forward with the review
of the data as you requested in your letter.
The referenced TH 36 AWF units were removed during the fall of 2002. The before
period you suggest is the year 2001 and part of 2002. I have also included the year 2000
in this before - removal analysis. The after period you suggest is 2003 and half of 2004,
through July 1. The availability of 2004 data is limited to what has been entered into the
system up to this time. The latest crash records currently available for 2004 occurred in
March, thus the 2004 data has not been included here. Also, the fatal crash you refer to
in your letter occurred on July 18. I requested a copy of that crash report directly from
DPS and will provide comments about that crash later in this letter.
Crash records contain many types of information. The portions of the crash records that I
will utilize for this analysis involve the overall number of crashes and the injury status of
those crashes. I will lump the crashes into the year they occurred. The injury status of
crashes is expressed as severity A, B, or C. A is incapacitating, B is non - incapacitating,
and C is minor or possible injury. PDO severity is Property Damage Only. The
computer system also computes a crash rate for each intersection. This rate is expressed
as Crashes per Million Vehicles Entering the Intersection.
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Crashes and AWFs on TH 36
Oak Park Heights /Stillwater
Sep 24, 2004 Page 2
Starting at Osgood Ave /CSAH 24, the observed crash numbers and rates were as follows:
BEFORE REMOVAL OF AWF's. OSGOOD /CSAH 24
Year Crashes Severities Rate
2000 7 C -3, PDO -4 0.6
2001 9 B -1, C -6, PDO -2 0.7
2002 (1 Half) 8 C -2, PDO -6 1.2
AFTER REMOVAL OF AWF's, OSGOOD /CSAH 24
Year Crashes Severities Rate
2003 11 B -1, C -2, PDO -8 0.8
Next, at Greely /Oakgreen, the observed crash numbers and rates were as follows:
BEFORE REMOVAL OF AWF's, GREELY /OAKGREEN
Year Crashes Severities Rate
2000 7 C -1, PDO -6 0.6
2001 14 B -3, C -1, PDO -10 1.2
2002 (1 Half) 8 B -1, C -2, PDO -5 1.3
AFTER REMOVAL OF AWF's, GREELY /OAKGREEN
Year Crashes Severities Rate
2003 7 C -3, PDO -4 0.8
On Sunday July 18, 2004, at 9:38 PM, a fatal crash occurred at the intersection of TH 36
and Osgood Avenue. MnDOT obtained a copy of the crash report, as completed by the
State Patrol. This report records that this two- vehicle crash occurred as a result of an
Crashes and AWFs on TH 36
Oak Park Heights /Stillwater
Sep 24, 2004 Page 3
east -bound left - turning vehicle's failure to stop for a red left -turn arrow indication. This
turning vehicle collided with a west -bound motorcycle that was proceeding through the
intersection on a green indication. It is evident from reading this report that an AWF for
this intersection would not have influenced the outcome of this crash. Left -turn
indications are never a factor to the operation of an AWF and AWFs do not alert motorist
about the status of the left -turn indications at an intersection. Also, since the crash report
documents that the westbound vehicle had a green indication, then even if this
intersection had still been equipped with AWFs, the AWFs would not have been flashing
at that moment. Therefore I must conclude that the occurrence of this crash was not
influenced by the lack AWFs on the TH 36 approaches to this intersection.
Based on the crash figures and analysis presented above, I cannot support your
hypothesis that the crash rates at these two intersections have risen since the removal of
the AWF systems. Both intersections appear to be experiencing typical crash rate
fluctuations. At this time, a meaningful, negative trend in the crash data is not being
observed.
I am available to further discuss your concerns about this data and the effects of the
removal of these advance warning flasher systems. Please contact me directly using the
information provided below.
incerely,
Bieniek, P.E., PTOE
MnDOT Metro District
Traffic Engineering
651- 634 -2152
john.bieniek@dot.state.nm.us
cc: Rick Arnebeck, Metro Area Manager
Amr Jabr, Metro Traffic
Steve Misgen, Metro Traffic
Jolene Servatius, Metro Traffic