NCDOT Traffic Safety Unit Pre-Construction Conference May 2018 - PowerPoint PPT Presentation

NCDOT Traffic Safety Unit Pre-Construction Conference May 2018

Traffic Safety Unit 2016 Crash Facts – Statewide Summary 2

Traffic Safety Unit Mission Reduce Crashes and/or Severity of Crashes 3

Traffic Safety Unit Unit Work Groups / Areas Regional Field Traffic Safety Highway Safety Specialist Improvement Program Operations Mobility and Safety Safety Evaluation Safety Planning Information 4

Regional Field Operations Pre-Construction Conference May 2018

Regional Field Operations NCDOT Regional Offices Western Central Eastern Mobility and Safety Mobility and Safety Mobility and Safety Field Operations Region Field Operations Region Field Operations Region 6

Regional Field Operations Regional Traffic Role Public Officials Request Division/City Ordinances Citizen Request Field Investigations Speed Limits Work Zone Traffic Signals Signs School Zones Penalty $250 Markings Roundabouts HSIP Sites No Parking, Fatal sites No Trucks, No U-turns, etc... Countermeasures Turn Lanes AWS Realignment Plan Review Super elevation R/W, Directional Maintenance crossovers TIP Projects Funding Vulnerable User Signal Systemic Projects Signing Mobility Funds Recommendations Spot Safety HSIP Funds Markings $20 Million 12.1 Million $40 Million <$750K <$400K $400K to $1M Median Barrier Guardrail End Units Signing Markings 7

Regional Field Operations US 1 A (Main St) 8

Regional Field Operations 9

Regional Field Operations 10

Regional Field Operations US 1 A (Main St) 11

Regional Field Operations SR 1006 (Old Stage Rd) 12

Regional Field Operations 13

Regional Field Operations 14

Regional Field Operations SR 1006 at SR 1010 15

Regional Field Operations 16

Regional Field Operations 17

Regional Field Operations Spot Safety & Hazard Elimination Before After 18

Safety Planning Pre-Construction Conference May 2018

Safety Planning Safety Planning Group TEAAS application maintenance and enhancements Project Support / Large scale data linkages / Environmental STI Support / Safety Data issues Benefit Factors Document Bridge Design Alternative Analysis Speeds TEAAS / Crash Data Scoping Phase Address Safety Issues for a Management corridor or special concern (Shared with HSIP and TSIS) Transportation Road Safety Planning / STIP Reviews (300+ per year) Traffic Records 900+ TEAAS Coordinating application users Committee Fatal Notifications / Year-To-Date Crash Analyses / Collision Diagrams / Metrics / Crash Analyses Merger Team GIS Mapping / Ad-Hoc Queries Divisions Project Development MPOs / RPOs / SPOT Office Fatal Crash Review Customer Service Program Requests (900+ per year) (400+ per year) Regional Traffic Engineers for Municipalities / Media Consultant Requests Investigation MPOs / RPOs Citizens Divisions 20 (TIAs / Project Related)

Safety Planning Project Scoping • Identify patterns of crashes the project should address – Detailed Crash Analysis 21

Safety Planning Project Scoping • Identify patterns of crashes the project should address – Detailed Crash Analysis – Mapping • Helps to identify patterns • Helps to communicate safety concerns 22

Safety Planning Project Scoping • Identify patterns of crashes the project should address – Detailed Crash Analysis – Mapping • Helps to identify patterns • Helps to communicate safety concerns 23

Safety Planning Alternative Analysis • Compare the “Safety” of each Alternative – How??? 24

Safety Planning Alternative Analysis • Compare the “Safety” of each Alternative – How??? – Predictive Analysis utilizing Safety Performance Functions • Using crash, roadway, and traffic volume data to provide estimates of an existing or proposed roadway’s expected safety performance • Can be used to quantify the safety impacts of proposed transportation improvements 25

Safety Planning Alternative Analysis • Safety Performance Functions – Example: Base function for 2-lane rural roadway 26

Safety Planning Alternative Analysis • Methodology for Analyzing a Corridor Alternative – Break corridor down into “like” segments • Intersections, curves, tangents, etc. 27

Safety Planning Alternative Analysis • Methodology for Analyzing a Corridor Alternative – Break corridor down into “like” segments – Analyze each segment individually CMFs CMFs 28

Safety Planning Alternative Analysis • Methodology for Analyzing a Corridor Alternative – Break corridor down into “like” segments – Analyze each segment individually – Incorporate existing crash history 29

Safety Planning Alternative Analysis • Methodology for Analyzing a Corridor Alternative – Break corridor down into “like” segments – Analyze each segment individually – Incorporate existing crash history – Calculate predicted and expected crashes • Predicted -> Based on calibrated safety performance function • Expected -> Based on Empirical Bayes (EB) analysis Clue #1 Clue #2 Crash History at Large Crash History at Pool Of Reference Sites Treatment Site (Described by SPF) 30 α 1 − α

Safety Planning Alternative Analysis • Methodology for Analyzing a Corridor Alternative – Break corridor down into “like” segments – Analyze each segment individually – Incorporate existing crash history – Calculate predicted and expected crashes – Summarize results of each individual segment analyzed to get estimates for entire corridor 31

Safety Planning Alternative Analysis • Benefits of Alternative Analysis – Quantifies expected safety for each alternative • Allows safety to be part of the discussion when comparing all measurables (i.e. wetlands impacted, relocations, etc.) for each alternative – Often allows projects to move forward and not get mired down in subjective discussions 32

Safety Planning Strategic Mobility Formula 33

Questions / Discussion 34