Bring Back the Tram Again!

Steve Miller

Transport for London

Why “Bring Back the Tram Again!”?

• To distinguish from “Bring Back the Tram!” - my presentation to the 20th “International” Emme/2 User Group Meeting (Oct. 2006 – Seattle);

• To update the Emme/2 community on a project’s evolution;

• Not a cry for a nostalgic panorama of pre-war UK trams!

Transport for LondonTransport for London (TfL) is the integrated body responsible

for London's transport system.

Its role is:• to implement the Mayor's Transport Strategy for London• To manage the transport services across the capital for which the

Mayor has responsibility.

TfL manages:– London's buses, the Underground, the Docklands Light

Railway (DLR), Croydon Tramlink and London River Services

– Victoria Coach Station and London's Transport Museum – The red route network, Congestion Charge, and London's

4,600 traffic lights – A range of alternative transport initiatives including walking

and cycling

Public Transport Issues for London

Limited investment in new rail infrastructure

Limited potential to increase rail capacity

“Sweat the Assets”; i.e.:

• Spread the Peak (demand and supply)

• Increased crowding

Need to demonstrate Value for Money – Cost/Benefit Analysis

The Tram Scheme:Old Tram or New Tram?

Why a Tram?

• Relieve tube crowding

• Stimulate regeneration

• Improve accessibility

• Increased reliability

• Better connection between mainline stations

• Environmentally friendly mode of transport

• Cost efficient

• Connect target areas south of river

• Improve overall system efficiency of highway based public transport

A Tram is Efficient

Trams can move passengers far more efficiently than other vehicles

1 tram 2 - 4 buses 220 cars

Possible Route

New 16.5 km tramway

Core alignment:

Euston to Waterloo

30 trams per hour

Branches

North: to Kings Cross and

Camden Town

South: to Peckham and Brixton

15 trams per hour each branch

Alternative routes

Alternative routes

Alternative routes

Initial Assessments

Started in 1997: Intermediate Modes Studies

Then further Studies:– Tram v high-quality bus services– Tram was feasible and beneficial– Ruled out bus option due to capacity and attractiveness

Refined Progressively to demonstrate:

• Sound Business Case (BCR: 2.64:1)

• Road Traffic Impacts can be managed

Models available to TfL

• LTS (London Transportation Studies) Model

• Railplan

• SALT (SATURN Assignment of London Traffic)

• SALT-C (Congestion Charging)

• Micro-Simulation and Junction Models

LTS (London Transportation Studies) Model

• Strategic 4 Stage Model, based on legacy software and TRIPS/Cube

• Covers London and South East England

• Network representation is not that detailed

• 1016 zones

• Run for 2001, 2006, and then every 5 years to 2031

The Railplan Model

• Runs on EMME/2 usually under UNIX

• Public Transport Assignment model of London – Underground– Rail– Tram– Bus– Docklands Light Rail (DLR)

The Railplan Model

• Uses Size 16 licence

• 1,500-3,000+ Zones

• 50,000+ Links

• Distribution-Mode Split model outside Railplan – usually reliant on LTS

Railplan Features

Developed since 1988

Initially for the AM Peak Period only

All Public Transport sub-modes

Congestion in Route Choice

Quantifies social benefit of reduced crowding

Forecasts station flow patterns to aid station planning

Standard Railplan Model: Demand

Derived from LTS Model

Year Trips (3 Hrs)

2001 1,836,318

2011 2,195,962

Growth 2% p.a.

Standard Railplan: Model Dimensions

Network (2001 Base)

No. Zones 1,571

No. Nodes 14,648

No. Links 49,596

No. Services 1,836

Network Usage (2001 Base)

Mode Services Serv. Kms Pass. Kms

N Rail 949 41,470 9,195,488

Underground 125 13,778 2,826,332

Light Rail 6 615 67,120

Tram 4 471 24,575

Bus 752 77,433 998,301

SALT (SATURN Assignment of London Traffic)

• Covers the complete (Greater London) area in detail

• Slow to run

• No longer directly supported or used – difficult to find resources to develop and maintain a detailed network model over such a large area

• Demand derived from LTS

SALT-C (Congestion Charging)

• Designed to model the “Boundary Route” around CC Scheme

• Based on a cordoned SALT model for run-time efficiency

• Matrix Estimation, prior matrix from LTS via SALT

• Demand externally split between “YACS” and “NACS” on a sector – sector basis

• 615 zones

Micro-Simulation and Junction Models

• TRANSYT is the normal basis for such models

• Micro-simulation (VISSIM) increasingly adopted for the more complex areas

• Individual models are developed and validated to represent specific junction groups

New Models For the Tram

A New family of models: CRISTAL

(Cross River Study of Trams Across London)

• CRISTAL-H (Highway – SATURN)

• CRISTAL-P (Public Transport – EMME/2)

• CRISTAL-J (Junctions – TRANSYT and LINSIG)

• CRISTAL-M (Micro-Simulation – VISSIM)

• CRISTAL-D (Demand or Mode Shift)

CRISTAL Models: Overview

RailplanPT

SATURNStrategic Highway

TRANSYTJunction

VISSIMMicrosimulation

Mode Share / Dem

Revised Signal Timings

Revised Signal Timings

Flow Changes

Flow Changes

Demand across the Thames

Westminster, Waterloo and Blackfriars Bridges: Summary of Travel Demand (AM Peak Hour)

0

5000

10000

15000

20000

25000

30000

35000

2006 Base 2016 Reference 2016 With CRT

Scenario

Ve

hic

le/P

as

se

ng

er

Flo

w (

AM

Pe

ak

Ho

ur)

CRT

Bus

Taxi

HGV

Car/LGV

Current State of Models : CRISTAL_H

Based on SALT-C

615 zones expanded to 697 zones

New treatment of taxi user class

AM Peak hour model validated

PM Peak Hour model validated

IP model not yet developed

AM Peak Hour Demand (PCUs/hr)  YACS

(Accept C.Charge)

NACS (Divert around

Zone)

Total

LIGHT 77,000 254,000 331,000

HEAVY 36,000 12,000 48,000

TAXIS 20,000   20,000

Total 133,000 266,000 399,000

Highway traffic flows (AM Peak Hour)

Current State of Models : CRISTAL-P

Based on Railplan

• 1571 zones expanded to 1645 zones

• AM Peak model validated

• PM Peak and IP models not yet developed

Public Transport Demand TransferredForecast LU Crowding Relief (AM Peak Period)

4-8% reduction in demand on most crowded services in central London – Northern, Victoria and Piccadilly

over 400,000 travellers on Tube in AM Peak will benefit

Slight increase in demand along a stretch of the Central line, Bank to Holborn

Current State of Models : CRISTAL-J

• 14 Individual local models developed and validated for AM and PM Peak hours

• Forecasts produced on operational aspects of traffic flows with or without Tram

• Mainly using TRANSYT and LINSIG for individual signal groups

Current State of Models : CRISTAL-M

• VISSIM Model was developed from a series of local models used previously

• Adequate to confirm general principles of scheme operation – interaction between tram and general traffic not readily handled in static models

• Route corridor being confirmed at this stage

• Initial model will be expanded and developed for the chosen route corridor

Current State of Models : CRISTAL-M VISSIM photo - BAYLIS ROAD / WATERLOO ROAD- Work in progress

Current State of Models : CRISTAL-D

• Previous Demand model was developed using EMME/2

• This has been refreshed for CRISTAL

• Now complies with DfT Advice (“WebTAG”)

Trip Frequency

Mode Choice (m)

Trip Distribution (d)

Assignment

Assignment Costs

Composite Costs (d)

Composite Costs (d,m)

HIGH

LOW

sensi

tivity

of re

sponse

s

Trip Frequency

Mode Choice (m)

Trip Distribution (d)

Assignment

Assignment Costs

Composite Costs (d)

Composite Costs (d,m) Trip Frequency

Mode Choice (m)

Trip Distribution (d)

Assignment

Assignment Costs

Composite Costs (d)

Composite Costs (d,m)

HIGH

LOW

sensi

tivity

of re

sponse

s

Convergence

CRISTAL-D Convergence Criteria:

• WebTAG % relative GAP < 0.1

• Benefits as % of network costs >= 10 * GAP

• Change in CRT demand < 0.5%

• Change in PT demand < 0.5%

• Change in highway demand < 0.5%

Future Year Modelling – Results2026 IBC RUN, SC359 – Iteration 3Post-Demand Model Results Compared to the Fixed Matrix Assignment

2026 IBC RUN, SC359 – Iteration 3

Post-Demand Model Results Compared to the Fixed Matrix Assignment

Around 800 Highway trips have transferred to PT and ‘slow modes’.

Overall increases in demand (181 trips) and benefits (959 pass-hrs) indicate that improvement in PT times is sufficient to compensate for increased journey times on highway

Fixed Demand Variable Demand Difference

DM SC515 DS SC359 (DS-DM)

PT Demand, pass 2,421,060 2,422,043 983CRT Demand, pass 63,836 66,925 3,089PT Benefits, pass-hrs -6,707 -6,500 207PT %GAP - 0.0002 -

Highway CAR Demand, pass 1,093,904 1,093,101 -803Highway Benefits, pass-hrs 2,349 1,184 -1,165Highway %GAP - 0.0147 -

Total Demand, pass 3,514,964 3,515,144 181Total Benefits, pass-hrs -4,357 -5,316 -959

Statistics, AM peak period

Model Operation

– Operation Platform – DOS / Windows– Batch File to operate– 3 to 5 iterations to converge

CRISTAL-HSATURN

Assignment models

CRISTAL-PEMME2

Assignment models

CRISTAL-DDemand model

Costs &DM

Demands

DS Demands

c on

verg

en

ce

Model Operation: Run Times

Highway Model 9.5 hours

PT Model <0.5 hours

Demand Model<0.25 hours

Per iteration 10 hours

So, a run still takes approx. 30 hours!

Scheme Costs and Benefits

Costs and Benefits (£m PV 2004 prices)

Tram Costs (600)

Revenue 250

User Benefits 1500- Time saving on trips 75%

- London Buses/Underground relief 25%

Economic Benefits 500

Non-User Benefits (200)

Benefit : Cost Ratio 2.8:1

Conclusions

• There seems to be a commercial case for a new Tram in central London

• Congestion Charging has offered some highway capacity for the core section

• The tools and data are available to develop robust forecasts of demand, traffic impacts and benefits

• EMME is an important part of the toolkit

• However, despite the commercial case, there remains issues of political risk and availability of funds

A Vision of the Tram

www.tfl.gov.uk