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31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads • Statistically-based prediction methods require significant efforts in crash data collection and long periods to observe crash occurrence • Defining the optimum design standard from crash data is a reactive approach • Traffic conflict studies can mitigate this issue using a short time survey to count the Parameters and statistical modeling for comparison of number and severity of traffic conflicts which are assumed as surrogate measures of safety. simulated and observed traffic conflicts. A case study on 2+1 • Short 2+1 passing sections can limit the ability to disperse traffic platoons and it may lead road sections to hazardous maneuvers (aggressive lane changing, increase of conflicts) Presenter: Carmelo D’Agostino 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads • Statistically-based prediction methods require significant efforts in crash data collection • Statistically-based prediction methods require significant efforts in crash data collection and long periods to observe crash occurrence and long periods to observe crash occurrence • Defining the optimum design standard from crash data is a reactive approach • Defining the optimum design standard from crash data is a reactive approach • Traffic conflict studies can mitigate this issue using a short time survey to count the • Traffic conflict studies can mitigate this issue using a short time survey to count the number and severity of traffic conflicts which are assumed as surrogate measures of number and severity of traffic conflicts which are assumed as surrogate measures of safety. safety. • Short 2+1 passing sections can limit the ability to disperse traffic platoons and it may lead • Short 2+1 passing sections can limit the ability to disperse traffic platoons and it may lead to hazardous maneuvers (aggressive lane changing, increase of conflicts) to hazardous maneuvers (aggressive lane changing, increase of conflicts) Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work

31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads • Statistically-based prediction methods require significant efforts in crash data collection and long periods to observe crash occurrence Observed VS Predicted Traffic Conflicts • Defining the optimum design standard from crash data is a reactive approach • Traffic conflict studies can mitigate this issue using a short time survey to count the One of the main problem in simulated conflicts study is the validation number and severity of traffic conflicts which are assumed as surrogate measures of of simulation results against real world conditions. safety. • Short 2+1 passing sections can limit the ability to disperse traffic platoons and it may lead The aim of the paper is to assess the reliability of traffic conflict to hazardous maneuvers (aggressive lane changing, increase of conflicts) measures obtained by microsimulation against real world observation. Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads • simulated conflicts (VISSIM and SSAM) Observed VS Predicted Traffic Conflicts • observed conflicts One of the main problem in simulated conflicts study is the validation of simulation results against real world conditions. The aim of the paper is to assess the reliability of traffic conflict measures obtained by microsimulation against real world observation. Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work

31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads • simulated conflicts (VISSIM and SSAM) • simulated conflicts (VISSIM and SSAM) • observed conflicts video recording and analysis of vehicle • observed conflicts video recording and analysis of vehicle trajectories in the merging area on 2+1 roads. Starting from those trajectories in the merging area on 2+1 roads. Starting from those data, trajectories were extrapolated and conflicts detected and data, trajectories were extrapolated and conflicts detected and analyzed. analyzed. studies focus only on lane changing conflicts in three locations in Poland Kra ś nik Ż yrardów Piaski Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Calibration of microsimulation model Simulated conflicts The aim of the calibration was to obtain a reliable share of platooning vehicles in simulation environment. • Estimation by SSAM software using micro-simulation trajectory outputs of VISSIM, • The analysis included lane-changing conflicts estimated for TTC higher than 1.0 sec and Comparison of micro- less than 5.0 sec, simulation results after the • Passing lane lengths varying from 500 m to 1200 m with steps of 100 m calibration versus collected data. • Traffic volume was varied from 300 to 1200 veh/h/dir with a step of 100 veh/h/dir, (80 simulation scenarios) Mean Absolute Percentage • More detailed evaluation was carried out by varying the merging length from 50 to 250 m Error for all simulation runs with a step of 50 m (55 simulation scenarios). was 8.1%. • 5 hours simulation run time and warm-up time of 30 minutes for each simulation. Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work

31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads 1 hour Traffic volume Traffic volume - H veh number of In total 10 hours of video recording were analyzed to evaluate conflicts, on the Roadway interval [veh/hour] [veh/hour] conflicts merging area of 6 2+1 segments with different traffic condition and length of 471 274 1 8 the additional lane. 457 274 Ż yrardów 1 Observed 518 299 2 8 450 263 Observed conflicts 201 84 1 7 185 103 Kra ś nik 1 conflicts 219 94 2 11 183 101 407 99 1 14 376 107 Piaski 1 610 125 2 6 381 105 345 92 1 2 403 124 Piaski 2 371 84 TTCmin = V*S(TTC)car 2 2 395 121 Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 31 st ICTCT Conference - Porto, Portugal on 25 th – 26 th October 2018 Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Parameters and stat. modeling for comparison of sim. and obs. TC. A case study on 2+1 roads Analysis of Analysis of vehicle vehicle trajectories trajectories Video were analyzed frame by frame (25 Hz), vehicle trajectories were identified by using a software for image analysis able to correct distortion of images, by imputing real measures of fixed points in the frames. Introduction Objectives Method Observed Vs Predicted Future work Introduction Objectives Method Observed Vs Predicted Future work