Reliability and Safety Prediction for Planning

Transcription

1 Reliability and Safety Prediction for Planning presented by Rich Margiotta, Cambridge Systematics Beth Alden, Hillsborough County December 7, 2016

2 Background Describe the effort to inject operations and safety into the Hillsborough long range plan update Needed a tool to predict travel time reliability and safety measures Desire to make available to all Florida MPOs

3 Background FDOT funded a project to implement Travel Time Reliability tools developed under the Strategic Highway Research Program 2 (SHRP2) One of these was the SHRP2 Project C11 tool, a sketch planning tool for studying reliability impacts and costs for individual projects Team decided to be more useful, the tool could updated and extended to work with a travel demand forecasting model 3

4 Background (cont.) Hillsborough County agreed to be the test case Team developed an analysis procedure to work with the loaded network file from the TBRPM Allows the consideration of Operations and Safety projects to address deficiencies Produces reliability and crash-related performance measures Safety prediction was added because of the high interest for the LRTP update Analysis incorporated into Imagine

5 Basic Structure Crash Data TBRPM Loaded Network HSM SPFs By Link SHRP 2 C11 Reliability Prediction FHWA Desk Reference CRFs A Safety Analysis Reliability Analysis B HERS Model Impact Factors Costs Corridor Analysis TOPS-BC O&M Costs Safety Project List Benefits/ Cost Operations Project List 5

6 Reliable travel means that unpredictable circumstances do not cause lengthy, unpredictable, and frustrating delays. Unpredictable Circumstances Inclement Weather Fluctuations in Demand Crashes Work Zones Poorly Timed Traffic Signals Do Not Cause Unpredictable Delays. Reliable travel: Most trips take about the same length of time. Under these conditions, users can expect to arrive on-time without worry and without unexpected delay. Unreliable travel: Trips lengths are highly variable. It is difficult to judge how long a trip will take before making a trip and users often will build in extra time to ensure that they will arrive on-time. These users expect there to be unpredictable delay. 6 Travel Time

7 Travel Time Reliability Number of Trips (in Thousands) Free Flow Travel Time = 5.5 min Average Travel Time = 10.7 min 80 th %ile Travel Time = 14.5 min th %ile Travel Time = 16.5 min Reliable Travel Failing Speeds Travel Time (in Minutes) The ratio of actual travel time to free flow travel time is 2.63 (14.5/ 5.5 = 2.63 travel time index (TTI))

8 Current Project FDOT received a grant from FHWA to implement formally the SHRP2 tools, including: Develop user-grade tool for the C11 sketch planning TDF post-processor; update relationships Make available to all Florida MPOs New Highway Capacity Manual reliability procedure Adding reliability and operations considerations to the FDOT planning and project programming 8

9 Post-Processor Improvements Revised the reliability prediction algorithm with NPMRDS to include signalized arterials Incorporated recently developed Florida-specific Safety Performance Functions Expanded range of operations and safety project types Accessible now by planners rather than researchers 9

10 Freeway Relationship

11 Arterial Relationship

12 Post-Processor Inputs Input screen parameters Loaded network file from Cube Corridor definition file 12

13 Corridor Definition File ANODE BNODE DIRECTION CORRIDOR FROM_STREET TO_STREET Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd Manatee / Hillsborough Co Line Big Bend Rd CORRIDOR NAME NO. SIGNALS US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 US 41 (Hillsborough Co) 5 13

14 Tool Interface

15 Tool Interface

16 Tool Interface

17 Reliability Results

18 Safety Results

19 Next Steps Finish testing with Hillsborough User and Technical Manuals Make available to all Florida MPOs Ongoing support from FDOT

20 Reliability and Safety Post-Processing Tool presented to Hillsborough MPO and FDOT presented by Tazeen Mahtab Rich Margiotta November 14, 2016