1. Multi-objective Analysis For Passengers’ Routing Using Car/Bicycle
Encontro com a Ciência e
Tecnologia em Portugal
Centro de Congressos de Lisboa 3 a 5 julho, Lisboa, Portugal
Multi-objective Analysis For Passengers’ Routing Using Car/Bicycle
Área Científica
Ciências da Engenharia e Tecnologia
Behnam Bahmankhahª, Margarida C. Coelhoª 
aCentre for Mechanical Technology and Automation (TEMA), Mechanical Engineering Department, University of Aveiro
Abstract
Regarding the individual and public benefits of cycling, people are willing to use more environmentally friendly transportation modes, such as cycling, to do short-distance trips in urban areas.
This study evaluates in an integrated manner the traffic performance, pollutant emissions and safety between bicycles and motor vehicles using Fast Non-Dominated Genetic Algorithm (NSGA-II) method.
The methodology was applied based on a real case study in a network in the city of Aveiro, Portugal. The analysis was based on a microscopic approach using VISSIM traffic model together with VSP methodology for emissions estimation and SSAM model for safety.
The results showed that bicycle demand increment improves emissions situation while we can not conclude the same results regarding safety and traffic performance. Replacing existing traffic light by a two-lane roundabout can led to significant reduction in emissions and traffic improvement while the safety level decreased. Since the same trade-off was associated with the results of route assessment, the Multi-objective analysis was applied for selected case studies.
Background
Individual and public benefits of the bicycle;
Health benefits
Environmental benefits
Economic benefits
Social benefits
Transport benefits
Almost half of all car trips in EU were shorter than 5 km in 2014.
Safety concerns of cycling;
45,000 cyclists were injured in the US (57% at intersections) in 2015
Among 818 killed cyclists, 27% at intersections (NHTSA, 2017)
2,112 cyclists were killed in the EU in % of cyclist fatalities occurred in urban areas (EC, 2016)
Main objectives
Development of multi-objective model in urban transportation to optimize the car/bicycle routing
Three dimensional Pareto Fronts were expressed through traffic performance, road safety, emissions and optimized using the fast Non-Dominated Sorting Genetic Algorithm (NSGA-II).
Methodology
Results
a) Entry of the network (Three-leg Intersection)
a.3) The multi-objective analysis for optimal bicycle demand solutions.
b) All the alternative routes between Origen & Destination
c) Exit of the network (Two-lane Roundabout) – Future Work
Conclusions
The presence of bicycles may dictate a trade-off in the network.
Emissions
Safety
Since the existing trade-off between the results are associated with different performance measures, the multi-objective analysis can be useful and informative.
Different traffic volumes, speed limits, type of intersection or roundabout design features may result in different safety outcomes.
Fig 3 / Three-leg Intersection with fixed time operation of traffic lights
Source:
a.1) Increasing bicycles demand
(from 9 to 270 bph)
Reduction in emissions 6-9%
Travel time increased from 94.1 s to s
Number of conflicts increased 27%
Fig 4 / Conflict types and Relationship between observed and simulated conflicts.
a. 2) Conversion of traffic lights by
a two-lane Roundabout
Significant reduction in CO2, NOX and HC
Reduces the number of stops and conflicts
More severe conflicts and potential crashes
Fig 5 / Hotspot Conflicts location for the baseline (left) and roundabout (right).
Crossing Conflicts – Red color
Lane Change - Blue color
Research Problem
Data Collection
Scenarios
Alternative Routes
Traffic Model
(VISSIM)
Calibration
Validation
Objectives
Literature Review
Emission Model (VSP)
Safety
Model (SSAM)
Survey & AHP
Alternative Routes for Motor Vehicles (II)
Alternative Routes for Bicycles (III)
Outputs (I)
Multi-objective Analysis
Travel-Time min: Route A
Vehicle (401 s) and Bicycle (461 s)
Emissions min: Route C
CO2 (176.2 g/km) and NOx (0.263 g/km)
Safety max: Route C has the minimum
conflicts while TTC was approximately
same for A, B, C, D .
Fig 6 / Layout of alternative routes coded in PTV VISSIM 7.
The results of multi-objective analysis represent route C as the best option for both bicycle and motor vehicle users.
Fig 7 / Layout of two-lane roundabout.
Source:
Assessing driving variability of bicycle-vehicle interaction at two-lane roundabouts: a multi-objective assessment based on traffic performance, emissions and safety.
Safety
Emissions
Traffic performance
Fig 1 / Methodology Framework.
Safety indicators: TTC, PET, MaxS, DeltaS, DR Emissions: CO2, CO, NOx, HC
Traffic performance: travel time, queue, speed, stops
Acknowledgements
B. Bahmankhah acknowledges the support CRUiSE project [PTDC/EMS-TRA/0383/2014] is funded within the Project Reforçar a Investigação, o Desenvolvimento Tecnológico e a Inovação (Project RIDTI) and supported by the European Community Fund FEDER. Also this work was supported by FEDER and National Funds through FCT – Portuguese Science and Technology Foundation within the Strategic Project UID-EMS
Fig 2 / Case Study in Aveiro (UA – Glicínias Shopping & UA - Train Station).