Institute for Transport Studies FACULTY OF ENVIRONMENT IAPSC Monday 11 th June 2012 Modelling LEZ and Demand Management measures in the City of York using Detailed Traffic-Emission Tools Dr James Tate Lecturer (50% Research) j.e.tate@its.leeds.ac.uk
CONTENTS Background Detailed, coupled traffic vehicle emission modelling Framework & demo. The Models: configuration and calibration Traffic microsimulations Instantaneous emission model PHEM (Emission factors, grams/ km) Emission contributions Policy evaluation (AQAPs) LEZ scenarios Demand Management Conclusions Work in-progress < IAPSC 11/06/2012 - Slide 1 / 25 >
BACKGROUND Changing vehicle fleet: fuel type, size, technologies e.g. driver assist systems Greater optimisation of the environmental performance of modern diesel vehicles to the legislated drive-cycles which don t reflect real-world driving Fig. Speed profile used for type approval purposes (New EU Drive-Cycle) NEDC - Speed Profile Speed (kmh 1 ) 0 20 40 60 80 120 0 200 400 600 800 1000 1200 1400 Time (seconds) Acknowledged limitations of average-speed vehicle emission models e.g. NAEI, EFT, COPERT, HBEFA etc. Reliability of emission factors, particularly NO X Their resolution means they cannot account for traffic congestion and local driving conditions In-direct linkage with traffic monitoring and/ or models Absence of methods to verify/ calibrate models to on-road ( real-world ) conditions < IAPSC 11/06/2012 - Slide 2 / 25 >
MODELLING FRAMEWORK Coupled micro-scopic traffic & instantaneous emission model < IAPSC 11/06/2012 - Slide 3 / 25 >
TRAFFIC MICROSIMULATIONS S-Paramics < IAPSC 11/06/2012 - Slide 4 / 25 >
DETAILED TRAFFIC-EMISSION MODELLING ILLUSTRATIVE VEHICLE TRAJECTORY Euro 4 diesel car speed and emissions time series Speed (km.h 1 ) 0 20 40 60 Naburn Ln Forlands Rd Heslington Ln Broadw ay East Hospital Fields Rd 0 100 200 300 400 500 600 700 Fuel (g.sec 1 ) 0 1 2 3 4 Naburn Ln Forlands Rd Heslington Ln Broadw ay East Hospital Fields Rd 0 100 200 300 400 500 600 700 NO X (mg.sec 1 ) 0 20 40 60 80 Naburn Ln Forlands Rd Heslington Ln Broadw ay East Hospital Fields Rd NOx NO2 0 100 200 300 400 500 600 700 PM (mg.sec 1 ) 0.0 1.0 2.0 Naburn Ln Forlands Rd Heslington Ln Broadw ay East Hospital Fields Rd 0 100 200 300 400 500 600 700 Time (seconds) < IAPSC 11/06/2012 - Slide 5 / 25 >
TRAFFIC MICROSIMULATIONS 1 TRAFFIC DEMAND Average weekday (May 2011) Automatic Traffic Count (ATC) data Manual counts J ANPR surveys (19 th May, 0700 1900hrs) TIME PERIODS AM, Inter-Peak (IP), PM and NIGHTtime 24-hour weighted average CALBRATION Demand/ Flows (DMRB procedure, GEH statistic) + Vehicle type proportions ( ± 1% ) Car, Van, HGV (rigid & articulated), Bus, Coach SIMULATIONS Harvest ALL vehicle trajectories (1Hz) 10 replications per time period 1 Fulford corridor S-Paramics network originally developed by David Preater (Halcrow, 2009)
INSTANTANEOUS EMISSION MODEL PHEM version 10.4.2. TUGraz (Technische Universität Graz, Austria) A comprehensive power-instantaneous emission model for the EU fleet Simulates fuel consumption (FC) and tail-pipe emissions of NO X, NO 2, CO, HCs, Particulate Mass (PM), Particle Number (PN) Whole European vehicle fleet: Euro 0 to Euro 5 Petrol, diesel and hybrid powertrains Light and Heavy-duty vehicles etc. Simulations: Consider all driving resistances including GRADIENT Gear shift model Transient engine maps (with time correction functions) Thermal behaviour of engine, catalyst, SCR etc. Validated in a laboratory (chassis dynamometer) with real-world and micro-simulated speed profiles/ drive-cycles
REMOTE SENSING VEHICLE EMISSIONS Surveying the vehicle fleet on the road Camera (Number plate) Vehicle Detector (Speed andacceleration) Emission ratios From peak exhaust plume conc. Source/Detector Emissions Analyser (Common Configurations) Mirror Box ESP RSD-4600 instrument www.esp-global.com Source Detector NO / CO 2 CO / CO 2 HC / CO 2 & PM Predict NO X and NO 2 / CO 2 Local measurements 4-days surveys September 2011 > 10,000 valid records < IAPSC 11/06/2012 - Slide 8 / 25 >
NO X EMISSION FACTORS Comparison with remote sensing measurements Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 2.5 Car_diesel Car_petrol Van 2.0 NO X (grams/km) 1.5 1.0 0.5 0.0 Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 Greater degradation of petrol engines/ emission controls Euro class Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 < IAPSC 11/06/2012 - Slide 9 / 25 >
NO 2 EMISSION FACTORS Light-duty vehicles Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 Car_diesel Car_petrol Van 0.4 NO 2 (grams/km) 0.3 0.2 0.1 0.0 Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 Euro class Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 < IAPSC 11/06/2012 - Slide 10 / 25 >
NO X EMISSION FACTORS Heavy-duty vehicles 16 HGV_artic E0 E1 E2 E3 E4 E5 E6 HGV_rigid NO X (grams/km) 14 12 10 8 6 E0 E1 E2 E3 E4 E5 E6 Euro class E0 E1 E2 E3 E4 E5 E6 Bus Coach NO X (grams/km) 30 20 10 E0 E1 E2 E3 E4 E5 E6 Euro class
PM EMISSION FACTORS Light-duty vehicles Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 Car_diesel Car_petrol Van 0.4 PM 10 (grams/km) 0.3 0.2 0.1 0.0 Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 Euro class Euro0 Euro1 Euro2 Euro3 Euro4 Euro5 Euro6 < IAPSC 11/06/2012 - Slide 12 / 25 >
PM EMISSION FACTORS Heavy-duty vehicles E0 E1 E2 E3 E4 E5 E6 HGV_artic HGV_rigid 0.6 PM 10 (grams/km) 0.5 0.4 0.3 0.2 0.1 E0 E1 E2 E3 E4 E5 E6 Euro class E0 E1 E2 E3 E4 E5 E6 Bus Coach 1.5 PM 10 (grams/km) 1.0 0.5 E0 E1 E2 E3 E4 E5 E6 Euro class
EMISSION CONTRIBUTIONS: NO X (%) 0 10 20 30 40 CAR-petrol CAR-diesel VAN HGV COACH BUS < IAPSC 11/06/2012 - Slide 14 / 25 >
EMISSION CONTRIBUTIONS: NO 2 (%) 0 10 20 30 40 50 60 CAR-petrol CAR-diesel VAN HGV COACH BUS < IAPSC 11/06/2012 - Slide 15 / 25 >
EMISSION CONTRIBUTIONS: PM 10 (%) 0 10 20 30 40 CAR-petrol CAR-diesel VAN HGV COACH BUS < IAPSC 11/06/2012 - Slide 16 / 25 >
POLICY EVALUATION SCENARIOS: Bus LEZs Euro 3 or better Euro 4 or better Euro 5 or better HYBRIDs on high freq. services Heavy Vehicle (HV) LEZs Euro 3 or better Euro 4 or better Euro 5 or better SCENARIOS: Hypothetical changes to general traffic demand levels (all t periods) 90% 95% BASE (100%) 105% 110% Light- & Heavy-duty LEZ Lights Euro 1, HV Euro 4 or better Lights Euro 2, HV Euro 4 or better
RESULTS: Low Emission Zone scenarios SCENARIO NO X (%) NO 2 (%) PM (%) Bus LEZ Euro 3-4.3-0.12-8.5 Euro 4-5.8-0.38-9.7 Euro 5-10.6-3.38-9.4 HYBRID Bus HYBRID Bus Service 7-3.35-1.52-1.62 Heavy- Vehicle LEZ Light- & Heavy-duty LEZ Euro 3-5.8 0.57-12.2 Euro 4-13.8-1.01-21.1 Euro 5-21.7-7.72-20.2 Lights Euro 1 * Heavy-duty Euro 4 Lights Euro 2 * Heavy-duty Euro 4-14.0 (-0.2) -1.27 (-0.26) -21.7 (-0.6) -14.3 (-0.5) -0.75 (+0.26) -23.3 (-2.2) < IAPSC 11/06/2012 - Slide 18 / 25 >
RESULTS: Demand management 20 Demand_change Change in total emissions (%) 10 0-10 90 95 100 105 110 Demand level (%) < IAPSC 11/06/2012 - Slide 19 / 25 >
CONCLUSIONS Method Have demonstrated detailed, coupled traffic-vehicle emission simulations are now feasible Emission Factors are in agreement with vehicle emission remote sensing measurements The approach, moving towards a virtual representation of traffic networks and the local vehicle fleet: represents a step-change in the capability, resolution and validity of vehicle emission assessments naturally encapsulates events that influence emissions e.g. Bus stops allows complex traffic situations (e.g. congestion) & management strategies to be assessed emerging vehicle technologies and control systems can be evaluated Allows the distribution of emissions through urban streets and intersections to be mapped < IAPSC 11/06/2012 - Slide 20 / 25 >
CONCLUSIONS Results LEZ policies that target larger, more polluting diesel categories are predicted to deliver: Substantial reductions in tail-pipe PM emissions E.g. Bus Euro 4 LEZ 10%, Heavy-duty Euro 4 LEZ 21% And reductions in NO X emissions E.g. Bus Euro 4 LEZ 6%, Heavy-duty Euro 4 LEZ 14% Extending LEZ restrictions to older passenger cars and vans would result in nominal emission savings Sustainable Transport measures that lower general traffic demand, are expected to effect a proportionally greater reduction in vehicle emissions E.g. 10% reduction in traffic 27% NO X AM peak, 18% NO X weekday Conversely the penalty for not managing traffic demand effectively are great
RECOMMENDATIONS It is critical that the 2014 Euro 6 diesel emission standards are more effective at controlling NO X emissions in urban driving conditions The emission performance Euro 6 diesel vehicles are assessed at the earliest opportunity (chassis dynamometer & remote sensing) A package of priority measures are progressed: Hybrid Buses to operate high frequency services, e.g. P&R, through AQMAs + Hybrid powertrain optimised for the route A feasibility study is carried out for a Euro 4 Bus LEZ. In Fulford this would require 30% of vehicles to be upgraded The benefit of these policies is a 10% NO X emissions (24-hour average) Further development and application of the microscopic traffic instantaneous emission modelling framework
WORK IN-PROGRESS York LEZ feasibility study 2012 Modelling all of York s main roads providing traffic microsimulations (David Preater) 7 time periods (AM shoulder, AM, IP, PM, PM shoulder, Evening, NIGHTtime) Vehicle fleet specification enhanced: Vehicle sub-category weights & engine power to reflect observations (ANPR) Vans: sizes I, II and III with loadings specified for each size category (AEA, 2010) Buses: Single-Decker, Double-Decker and Bendy-Buses With separate Bus fleet breakdowns/ spec. for each service < IAPSC 11/06/2012 - Slide 23 / 25 >
TRAFFIC MICROSIMULATIONS S-Paramics ALL York Network < IAPSC 11/06/2012 - Slide 24 / 25 >
ACKNOWLEDGEMENTS FUNDING: Development of the Modelling framework And this demonstration via a EKT Transfer secondment 2010-11 Remote sensing work Current York LEZ feasibility study Mrs Elizabeth Bates, Mr Andrew Gillah Prof Stefan Hausberger et al. < IAPSC 11/06/2012 - Slide 25 / 25 >