TDOT’s Evolving Highway Safety

Bruce Aquila, Intergraph Corporation

Wednesday October 28th, 2015

Background• TDOT and Intergraph are

Valued Partners– Solutions

• TRIMS (1996)• HSIP (2006)• E-TRIMS (2008)• Image Viewer (2014)• SLD (2015)

– LRS/Geospatial Platform• MGE (1993)• GeoMedia (1999)

The Problem/Drivers - Things Change

• SAFETEA-LU – Changed way States look at

improving Roadway Safety– States develop a Strategic

Highway Safety Plan (SHSP)• Based on accurate/timely safety

data

– Established Highway Safety Improvement Program (HSIP)

– Identify High Risk Rural Roads Program (HRRRP)

FHWA Emphasis Areas

• Local & Rural Road Safety

• Pedestrian & Bicycle Safety

• Roadway Departure Safety

• Fatal/Incapacitating Injury Crashes

Drove modification to existing tools at TDOT

Ground Work

• TDOT produced a list of potential Safety Improvement Projects

• Software determined Sections, Spots and Intersection Locations

• Separate Highway types - Rural and Urban

• Compared Locations to Statewide Averages and Critical Rates

• Results contained many Locations on Prior Lists

Data - The Key

• Crashes collected by Public Safety

• TDOT determines location on network

• Crashes imported into TRIMS• TRIMS contains

Roadway/Traffic Data • System uses TRIMS data to

create Roadway Safety Analysis Locations

Getting Ahead of the Curve

• Flexible to Evolve as Priorities Change

• Use all Available Crash Attributes

• Include Project List Management in Tool

• Show prior Locations Studied/Improved

• Easy to Use/Available to more Users

Process starts by Creating a Study

• What Roads to Include?• What Date Ranges to

Study?• Criteria for Determining

Sections?• Define Required Confidence

Level Needed?

What if you want to use more than one study criteria?

Create Multiple Studies

• 3 years Crash History used for HSIP

• 6 years Crash History for HRRR

• For Corridor Analysis combine:– All Multi-lane Roadways or – Separate Divided and

Undivided

• Create Section Breaks for City Limits or Ignore

• Create Multiple Studies as Needed

Building a Study

• Flexible Analyzing Data

Steps in Creating a Study• Create Segments

– Breaks Roadways into Homogeneous Sections

• Calculate Intersection Entering Volume– Adds Traffic Volumes from all Legs of Intersection

• Create Locations– Creates Sections, Spots and Intersection Locations

• Calculate Rates– Statewide & Critical Crash Locations

Create a Study for Every Need

Build Project List

• Query the Study to meet Goals

• Query Roads to Include• Query Areas to Study• Create Criteria to include

Locations in Potential Projects List

• Include Multiple Criteria in List

• Evaluate potential projects from Final List

Which Roads to Include?

Narrow the Geographic Area

Build Criteria

Advanced Query Capability

Compare two column values

Advanced Query Capability

Compare a column to a value

Advanced Query Capability

Compare the sum of multiple columns to a value

Criteria Building - Column to Column• CRASH RATE• CRITICAL RATE• FATAL CRASH RATE• FATAL LANE DEPARTURES• FATAL PEDAL CYCLE CRASHES• FATAL PEDESTRIAN CRASHES• INCAP INJURY RATE• INCAP LANE DEPARTURES• INCAP PEDAL CYCLE

CRASHES• INCAP PEDESTRIAN CRASHES• LANE DEPARTURE CRASH

RATE• PEDAL CYCLISTS INCAP INJ• PEDAL CYCLIST KILLED• PEDESTRIANS INCAP INJURED

• PERSONS INCAP IN LANE DEPART.

• PERSONS KILLED IN LN DEPART

• SEVERE CRASH RATE• TOTAL CRASHES• TOTAL FATAL CRASHES• TOTAL INCAP INJURY

CRASHES• TOTAL LANE DEPARTURES• TOTAL PEDAL CYCLE

CRASHES• TOTAL PEDESTRIAN CRASHES• TOTAL PERSONS KILLED• TOTAL PERSONS INCAP

INJURED• OTHERS

Criteria Building

Criteria BuildingUse Sum Query to Add Two Column Values

Query for locations having total Fatal Lane Departure crashes + Incap Lane Departure crashes > 3

Query Results

Excluded locations are highlighted

Tracking Exclusions

• Certain Locations showed up Annually– Even after being addressed

• Built an Exclusions Database: – Monitors sections with

determinations made in past

• Exclusion Reason noted and Edited as required

• Exclusions highlighted on Query Results and Final Lists

Exclusions

Comments box used to update status of project

Final List

• Completed queries added to final Location List

• Listed Projects:– Analyzed to refine

potential projects– Stored in database until

Validation and Safety audits performed

Select Locations for Final List

List Management

Click Criteria Description and see the query that included the location

Exclude From List

Exclude Entry

Exclusions Used to Track Projects

Corridor Query

• Works like other queries:– Combines Adjacent like

Sections

• Averages AADT and Sums Crash Totals

• Crash Rates Re-calculated

• Separate Study with own List

Multi-County Corridor Study

Corridor Query – Fatal Bike/Pedestrian

Corridor Locations Fatal Crashes

Lessons Learned

• Safety Emphasis Areas continue to Evolve

• Good Reporting Tools needed to support these changes

• Roadway/Crash data quality improving

• Improved Safety crucial to Highway Needs Assessment

Questions

Bruce Aquila

Transportation Consultant

Intergraph Corporation

Bruce.aquila@intergraph.com

Thank You !!!