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MAINE Highway Safety Information System Liaison Meeting Chapel Hill, North Carolina September 10 - 11, 2015 Darryl Belz, P.E. Maine Department of Transportation
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Objective Implementation of the Highway Safety Manual Development of Maine Calibration Factors for the following facility types: Rural two-lane, two-way roads 2-Lane Undivided (R2) 3-Leg Stop Control (R3ST 4-Leg Stop Control (R4ST) 4-Leg Signalized (R4SG) Urban and suburban arterials 2-Lane Undivided (2U) 3-Lane including a TWLTL (3T) 4-Lane Undivided (4U) 4-Lane Divided (4D) 5-Lane including a TWLTL (5T) 3-Leg Stop Control (U3ST) 3-Leg Signalized (U3SG) 4-Leg Stop Control (U4ST) 4-Leg Signalized (U4SG)
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Calibration Team Dennis Emidy, P.E. Regional Traffic Engineer, MaineDOT Sarah LeBlanc, E.I. Assistant Engineer, MaineDOT Kara Aguilar, E.I. Assistant Engineer, MaineDOT Greg Costello Senior Technician, MaineDOT Edward Hanscom, P.E. Public Service Mgr II, MaineDOT
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The Project Manager, Bullwinkle
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5 Maine Conditions
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Replace default crash statistics with local values All facilities Crash severity and collision type Ratio of nighttime to total crashes Ratio of driveway-related crashes to total crashes (segments) Urban and suburban facilities Pedestrian adjustment factor Bicycle adjustment factor
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What We Did Calibration Factor Calculation Predicted Crash Frequency Calculation Data Collection Site Selection Facility Type Identification
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Step 1 - Facility Type Rural two-lane, two-way roads 2-Lane Undivided (R2) 3-Leg Stop Control (R3ST 4-Leg Stop Control (R4ST) 4-Leg Signalized (R4SG) Urban and suburban arterials 2-Lane Undivided (2U) 3-Lane including a TWLTL (3T) 4-Lane Undivided (4U) 4-Lane Divided (4D) 5-Lane including a TWLTL (5T) 3-Leg Stop Control (U3ST) 3-Leg Signalized (U3SG) 4-Leg Stop Control (U4ST) 4-Leg Signalized (U4SG 13 total facility types for calibration
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Step 2 – Site Selection 30 to 50 sites 100 crashes per year minimum for each site type Randomly select sites
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Step 3 – Obtain Data Obtain crash data Three full calendar years Obtain site characteristics data Appendix Part C, Table A-2 Some default values were used Presence of spiral curves Centerline rumble strips Automated enforcement Intersection red light cameras
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Data Needs for Calibration
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Data Needs (continued)
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Data Sources As-Builts Automatic Road Analyzer (ARAN) MaineDOT databases Route Log Mile Filter Map Viewer Transportation Information for Decision Enhancement (TIDE) Maine Crash Reporting and Analysis for Safer Highways (C.R.A.S.H) Google overhead imagery Google streetview
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ARAN Automatic Road Analyzer
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ARAN Capabilities Right of Way Video Roughness Pavement Distress Rutting Positioning - GPS Positioning - DMI Texture
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Panaramic Photo-Log 640 x 480 1920 x 1080
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Custom Angle Photo-Log Right Side View Rear View
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Upcoming Automation Roadway geometric data Cross slope Edge of pavement drop-off Horizontal curves Vertical curves Global Positioning System (GPS) coordinates Asset location data to within inches High definition right of way images Three high definition cameras (1920 x 1080 pixel resolution) Single 145 degree image every 4 millimiles (21.12 feet) Vertical clearance measurements
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Example Data Collection Results
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Step 4 – Calculate the Predicted Crash Frequency Step 1: Predicted crash frequency under base condition Segment: segment length and AADT Intersection: AADT for major and minor roads Step 2: Predicted crash frequency for non-base condition Calculate CMF using roadway characteristics data Step 3: Total crash frequency for the facility type IHSDM Crash Prediction Module was used for rural two- lane, two-way roadways HSM Spreadsheets were used for urban/suburban arterials
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Step 5 – Compute Maine Calibration Factor Calculate the SPF Maine calibration factor base on equation A-1 in Appendix A of HSM
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Maine Calibration Summary
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Maine Specific HSM Spreadsheet Set up for evaluating several alternatives at one intersection Maine-based calibration factors for overall crash rates are included Maine-based crash type and severity information replaces the default values Allowance for up to three additional crash modification factors has been included A crash cost tab has been added to estimate crash costs (and benefits) of intersection alternatives
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Maine Specific HSM Spreadsheet Original Spreadsheet developed by: Karen Dixon, Ph.D., P.E. Oregon State University School of Civil & Construction Engineering
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28 Maine Specific HSM Spreadsheet Example CMFs: Pavement Markings, Right Turn on Red, Flashing Beacons, Median Width, etc. Worksheet 2B -- Crash Modification Factors for Rural Two-Lane Two-Way Roadway Intersections
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Maine Specific HSM Spreadsheet Crash Costs and Benefits of Intersection Alternatives IntersectionIntersection Type Total Crashes per Year Crash Crashes per Year for Compariso n Unit Crash Costs ($)Crash Costs ($) Benefits ($) Alternative3ST (3-leg, 1-stop)ObservedEstimated EstimateTotalFIPDOFIPDOAnnual Pres WorthPresent 4ST (4-leg, 2-stop) PredictedExpectedto (fatal and(property (based onWorth 4SG (4-leg, signal) Compare injury)damage 10 only) years) Baseline/No-Build4ST3.002.342.57Expected2.570.931.6419620089001970621450393- Alternative 14SG-3.453.26Predicted3.451.142.2111840089001546451138201312193 Alternative 24SG-3.503.36Predicted3.501.192.3111840089001614551188323262071 Alternative 34ST-2.342.57Expected2.570.931.64196200890019706214503930 Alternative 44SG-4.473.99Predicted4.471.522.9511840089002062231517819-67426 Alternative 54ST-3.233.13Expected3.131.142.0019620089002414681777226-326832 Worksheet Source 3A 3B Discount Rate 6% dropdown menu inputsmanual inputs
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Local Calibration Case Study HSM with locally calibrated factors on a rural intersection study in South Berwick at State Routes 236 and 91 Five intersection alternative designs were evaluated and compared to the existing or “no-build” option For a comparison, the HSM was also used without the locally calibrated factors 2015 AASHTO Sweet Sixteen High Value Research Project Award
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Local Calibration Case Study Proposed Alternatives Alternative 1 Alternative 3 Alternative 2 Alternative 5Alternative 4
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Local Calibration Case Study Comparison
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Summary Calibration allows for HSM implementation in Maine Calibration factors developed for rural two-lane roadways and urban/suburban arterials (segments and intersections) using state-wide data Significant manual effort involved for some data collection Adapted the HSM spreadsheets for Maine implementation with alternative analysis Case Study shows the benefits of implementing local calibration factors
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Future for Calibration in Maine Develop localized calibration factors? 16 counties – probably too much effort and widespread differences 5 MaineDOT regional offices – factors for each regional HSM user 8 geographical regions with varying terrain and weather conditions By County? By Geography? By Region?
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Thank You Darryl Belz, P.E. Maine Department of Transportation 207-624-3275 darryl.belz@maine.gov
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