Title: TH 23CSAH 7 Road Safety Audit
1TH 23/CSAH 7 Road Safety Audit
2TH 23/CSAH 7 Road Safety Audit
- Background
- Data Collection and Review
- Field Review Observations
- Potential Mitigation Measures
3Background
- Purpose and Need for Road Safety Audit
- Intersection identified by City as safety problem
location - Recent fatal bike crash
- Road safety audit can identify potential safety
solutions - Pending Development north of TH 23
- Road Safety Audit Team
- Five Mn/DOT experts
- Minnesota State Patrol officer
- SEH traffic engineer
4Data Collection and Review
- Meeting with District 8 and Other Stakeholders
- Intersection Geometry and Traffic Control
- 4-lane expressway intersecting 2-lane road
- 55 mph speed limit on TH 23
- 40 mph speed limit on CSAH 7 north of TH 23 and
55 mph speed limit on CSAH 7 south of TH 23 - Right and left turn lanes on TH 23 right turn
lanes on CSAH 7 - Narrow median crossover (about 42 feet from edge
to edge) - TH 23 is uncontrolled
- Stop sign control for CSAH 7 and yield sign
control for median crossover - Bike crossing across east leg of intersection
5Data Collection and Review
- Traffic Volumes
- 5,800 to 5,900 veh./day on TH 23
- 3450 to 740 veh./day on CSAH 7
- 2,200 veh./day on CSAH 7 north of Country Club
Drive - 2,000 veh./day on Country Club Drive
- Future traffic increase due to anticipated
residential development north of TH 23 - Intersection does not currently meet MMUTCD
signal warrants
6Data Collection and Review
- Crash Data
- 17 crashes in approximately five year period
- One fatal crash and 11 crashes involving injuries
- Intersection crash rate is four times the
statewide average rate - 14 crashes were right angle type
- 12 crashes involved vehicles pulling away from
median crossover
7Field Review Observations
8Field Review Observations
- Geometric Design and Lighting
- Curve in CSAH 7 north of TH 23 and curve in CSAH
7 north of Country Club Drive - Jog in CSAH 7 north of TH 23
- Vehicles waiting in median left turn lanes can
limit sight distance for other traffic - Limited storage space for vehicles waiting in the
median crossover - Radii in NW and SE corners is tight for large
trucks - No end treatment for bridge railings on CSAH 7
bridge south of TH 23 - Existing street lighting
9Field Review Observations
- Signing and Pavement Markings
- Undersized signing for expressway intersection
conditions - SB STOP sign and median DO NOT ENTER signs
mounted too low - ONE WAY sign obscures shape of YIELD signs on
median - NB CSAH 7 STOP AHEAD sign too small
- Good route marker/directional signing identifies
intersection - Approaches have centerline, edge line, and lane
line markings - No pavement markings in median crossover area
- No yield line markings
- BIKE CROSSING signs are 30x30
- Delineator color wrong on curves
10Field Review Observations
- Other Observations
- No off-road pedestrian or bike facilities
- No development in any corners of intersection
11Potential Mitigation Measures
- General
- Grouped into short-term and long-term
improvements - Short-term measures not guaranteed to be
successful
12Potential Mitigation Measures
- Short-Term Improvements
- Upgrade signing to meet current expressway
intersection signing practices - Increase size of NB STOP AHEAD sign on CSAH 7
- Add BIKE ROUTE sign with LEFT ARROW sign on EB TH
23 - Increase size of BIKE CROSSING signs to 36x36
- Add flashers to BIKE CROSSING signs
- Change delineators on curves
- Add rumble strips along TH 23 edge lines
- Mark yield lines in the median crossover
- Reconstruct median ends and add defined pathway
for bike crossing - Add HAWK signal for bike crossing
- Increase corner radius in NW and SE corners of
intersection to accommodate large trucks - Add crashworthy end treatment to CSAH 7 bridge
railings
13Potential Mitigation Measures
- Long-Term Improvements
- Change intersection to grade-separated
interchange - Reconfigure intersection to provide offset left
turn lanes in median area - Add free right and acceleration lane for SB CSAH
7 movement - Reconfigure intersection to ¾ access intersection
- Reconstruct and realign CSAH 7/Country Club Drive
intersection
14Potential Mitigation Measures
- Other Considerations
- Provide sidewalks or trails along roadways
- Form Safe Communities Coalition
15Summary
- Alternative choices of improvements provided and
need more detailed evaluation by District 8 staff - Short-term improvements are only temporary
solution - Permanent solution can only be achieved through
long-term improvement