1 Element 1: The Systemic Safety Project Selection Process Element 1: 4-Step Project Selection Process

Objective Develop a prioritized list of locations that could benefit from systemic safety countermeasures – Prioritized = Risk assessment for future crash; answers to question if all elements are equally at risk. – Location = Specific sites from focus facility type; including segments, curves, intersections, etc. 2 Element 1, Step 2: Screen and Prioritize Candidate Locations

Outcome An assessment and rating of the focus facility type(s). Identify locations considered for systemic safety improvements. 3 Element 1, Step 2: Screen and Prioritize Candidate Locations

Data Needs Location of focus facility type – Signalized intersections – Horizontal curves – Divided corridors – Etc. Site specific crash information – Severity, – Crash type – Relevant contributing factors Traffic and geometric information – At minimum, for risk factors – Additional information may be needed for selecting countermeasure 4 Element 1, Step 2: Screen and Prioritize Candidate Locations

Element 1: Step 2 5 Element 1, Step 2: Screen and Prioritize Candidate Locations

Element 1: Step 2, Task 1 Identify Network Elements Analyzed Purpose: Identify the all locations from the focus facilities – A census, not a sample Resources: Road and intersection data Crash data at statewide and regional levels Element 1: Step 2, Task 1 6

Element 1: Step 2, Task 1 Identify Network Elements Analyzed Process: 1.Identify ALL locations from focus facility type. – Curves & Intersections: identify eligible locations – Segments:  Split corridors into elements with consistent traffic and design characteristics (i.e., cross section)  Identify logical segment endpoints 2. Are risk factors feasible for a systemwide analysis? – Did you notice anything that suggests a need to change risk factors? Element 1: Step 2, Task 1 7

Sample Segment & Curve 8

Element 1: Step 2, Task 2 Conduct Risk Assessment Purpose: Document the conditions (i.e., risk factors) at each location selected for analysis. Suggestion While collecting information about risk factors, consider what data might be needed to assign/select the countermeasure. Element 1: Step 2, Task 2 9

Element 1: Step 2, Task 2 Conduct Risk Assessment Resources: GIS Electronic inventories of roadway features and traffic characteristics Data collected as part of a field review Archives of as-built plans Aerial photography/street views Video logs Traffic control device inventories Traffic flow maps Element 1: Step 2, Task 2 10

Element 1: Step 2, Task 2 Conduct Risk Assessment Process: 1.Record roadway and traffic characteristics for the selected risk factors 2.Document crash history (particularly severe focus crashes) for each location. Element 1: Step 2, Task 2 11

Example Data Collected for Segments 12

Video Logs Edge Risk Assessment – See photos Lane Width Shoulder Width/Type Posted Speed Limit Curve Signing Sample Percent No Passing 13 2 – Usable Shoulder, Roadside with Fixed Objects 1 – Usable Shoulder, Reasonable Clear Zone 3 – No Usable Shoulder, Roadside with Fixed Obstacles 13  

Aerial Images for Segments Segment Access Points Curve – Visual Trap and Intersection 146/2011

Aerial Images for Intersections Skew Intersection on/near horizontal curve Railroad crossing Commercial Development in quadrants 15

Element 1: Step 2, Task 3 Prioritize Roadway Facilities Purpose: Use risk factors to assess locations’ risk. Identify top sites considered for countermeasure implementation. Element 1: Step 2, Task 3 16

Element 1: Step 2, Task 3 Prioritize Roadway Facilities Process: 1.Prioritize roadway facilities using one of two methods to weight risk factors: – Equal weight to risk factors  Identify the risk factors present for each location  Sum the total number of risk factors for each location  Prioritize locations based on number of risk factors present – Weighted risk factors  Assign relative weights to each risk factor  Calculate a score for each location  Prioritize locations based on total score 2.Set a threshold (the number of risk factors present or a weighted value) used to identify high-priority candidates. 3.Flag the locations above the threshold. Element 1: Step 2, Task 3 17

Example County Segment Prioritization Is the County’s entire system at-risk? – No, about 25% of their miles were determined to be a High Priority 18 Totals #%Mileage%  23%7.42%  45%17.94%  1621%75.319%  2836% %  2026% % -79%41.410% 77100% % RankCorridorRoute#StartEndLengthADT ADT Range RD Density Access Density Curve Critical Radius Density Edge Risk Totals Tiebreakers Edge Risk RD Density CNTY89 CSAH  CSAH40 NEW LONDON CORP LIMCSAH  CNTY89 CSAH-30MNTH  CSAH9 CR-90, WILLMAR CORP LIMCSAH  CSAH5 150TH AVE NW CSAH- 29CSAH  CSAH31 NEW LONDON CORP LIMMNTH  CSAH8 RENVILLE COUNTY LINE LAKE LILLIAN CORP LIM  CSAH4 CSAH-8CSAH  CSAH2 CSAH-10MNTH  CSAH4 CR-98CSAH  CSAH38 CSAH-40CSAH  CNTY89 CSAH  CSAH42 CSAH-7COUNTY LINE  CSAH9 CSAH-10 CSAH-40, REDWOOD ST 4.9 1,800  CSAH25 CSAH-5USTH ,315  ………… …… … ……………………… ………… …… … ……………………… CSAH1 MNTH-23PENNOCK CORP LIM  CNTY89 CSAH-3MNTH  CSAH2 ATWATER CORP LIMCSAH ,018  CSAH28 CSAH-2COUNTY LINE  Total Stars % That Gets Star --36%46%47%46%31% Element 1: Step 2, Task 1

Example County Curve Prioritization 19 Complete census of 504 curves 32 High Priority Curves (6%) 138 Curves in Proximity Chevrons in Place Stars#%#%  00%0  71%20%  255%41%  10821%10%  25050%20% %51% %143% Crashes Severe RoR Curve Count IDCorridorSegmentTotalSevereKABCPDOKA Radius (ft) Length Curve (ft) ADT Intersection on Curve Chevrons Visual Trap RankProximity Chevron Candidate 1001A1.01CSAH  2001B1.01CSAH  3001C1.01CSAH  4001D1.01CSAH  5001E1.01CSAH  6001F1.01CSAH  7001G1.01CSAH  8001H1.01CSAH  9001I1.01CSAH  10001J1.01CSAH  11001K1.01CSAH  12001L1.01CSAH Yes-  Installed 13001M1.01CSAH ,  14001N1.01CSAH Yes--  15001O1.01CSAH Yes--  16002A2.02CSAH  Yes 17002B2.02CSAH Yes--  -Yes 18002C2.02CSAH Yes--  -Yes 19002D2.02CSAH  Yes 20002E2.02CSAH ,  Yes 21002F2.02CSAH ,  Yes 22002G2.02CSAH  -Yes 23002H2.02CSAH ,  Yes ………… … … … … … … … … ………………………… ………… … … … … … … … … ………………………… ………… … … … … … … … … ………………………… ZH249.01CR Yes--  ZI249.01CR  Yes ZJ249.01CR  Yes Element 1: Step 2, Task 1

Example County Intersection Prioritization 20 Is the County’s entire system equally at- risk? – No, about 41% of their system is a High Priority #%  00%  00%  00%  811%  2130%  3346%  913% -00% 71100% Element 1: Step 2, Task 1