transport thursday 18 december 2014 - dynamic lane guidance

1Transport Thursday/GRS Seminar Presentation, 18th December 2014

Challenge the future

Dynamic Lane Guidance

Bart van Arem, Peter de Bakker & Wouter Schakel



Intelligent transport systems:

cooperation and automation



Tactical driving advice: Dynamic

Lane Guidance

ACC

predecessor

Dynamic Lane

Guidance

Route navigation

>2 km

Affordable positioning at lane level?

Which advice to give to whom and when?



Integrating geographical levels

direct

surroundings

x kilometre ahead

(e.g. 2 km)

regional

network

vehicle

dynamics

• Intelligent

camera

• eHorizon • Service Centre

• Traffic Management Centre

• enhanced

positioning

• GNSS

• (vehicle

sensor data)

• speed advice

based on on-

coming road

geometry and

speed limits

• current speed

limit from

traffic sign,

• speed advice

based on local

traffic situation

• speed, headway

and lane use advice

• dynamic maximum

speed

integrated speed, headway and lane use advice

vehicle

driving direction



Architecture



Dynamic Lane Guidance

2009 2011 2013 2015 2017

Connected Cruise Control

Phantom Traffic jams

Taking the Fast Lane

Dynamic Lane

Guidance

High performance vehicle

streams

2 PhD

vacancies



CiTG Transport & Planning

Traffic state estimation and advise algorithms

CiTG Geoscience & Remote Sensing

Lane Level Positioning

Research partners

8Challenge the future

Modes of GNSS positioning

GNSS – Global Navigation Satellite System (e.g. GPS)RTK – Real-Time Kinematic (Surveying) SF – Single FrequencyPPP – Precise Point Positioning DF – Dual Frequency


Earth

atmosphereionosphere

troposphere

satellite orbit & clock

receiver noise + multipath

1. Hardware2. Augmentation data3. Models & Algorithms

Error sources in GNSS positioning


Surveying-grade Mass-market

Hardware – GNSS receiver &

antenna


Real-Time Kinematic Precise Point Positioning

Infrastructure – global network of

reference receivers


Accurate models and smart

algorithms


GNSS observations- pseudo range- carrier phase- time stamp

- coarse satelliteephemeris

GNSS constellation

ionosphere

global tracking network (IGS, DLR)

Precise products- real-time satellite clocks- predicted satellite orbits- global ionosphere maps

User algorithm- recursive least squares- integrity monitoring- additional corrections(troposphere, solid Earth tide, hardware delays, carrier phase bias, carrier phase windup, …)

+-

+-

+-

+-

+-

+-+

-

+-

Single-frequency user

1 kbit/s

Single-Frequency Precise Point Positioning


Satellite availability Position accuracy

SF-PPP performance

kinematic real-time


Lane identification (A20)


Impression



Influencing traffic flow dynamics

Traffic state

estimation

Advice

algorithm

Data Advices

Traffic system

Traffic flow theory



Traffic state estimation

• Prediction

• To compensate data delay

• 1 min in future

• Extended Generalized Treiber-Helbing Filter (EGTF)

• Multiple data sources

• Used at lane levelFree flow: +85km/h

Congestion: -18km/h

time

space

driving direction



Advice algorithm

Yield advice

a a

b

b

a

b

Lane change/keep advice

Applicable destination

Speed/synchronize advice

a/b Trigger Short & safe headway

Congestion Free flow

Distribution advice

Acceleration adviceSpillback advice



Simulation results A20

Day 1: no spillback Day 2: spillback(from offramp & downstream section)

Penetration rate Compliance

Mea

n t

rav

el

tim

e d

elay

[s]

Penetration rate Compliance

Mea

n t

rav

el

tim

e del

ay [

s]

-49%-43%

+1% +14%

422

452

1262

Prins Alexander301

597

249

665

Gas station

317

1574

311

170

235

Nieuwerkerk a/d IJssel

347

1230

707

662

Moordrecht

327

2194

1

335

707

1194

1685

1982

2288

2587

2885

3281

3578

3979

4377

4675

4974

5372

5671

5869

6068

6319

6685

6964

7262

7760

8258

8606

9097

9356

9653

9951

10350

10847

11147

11646

12022

A20/A

16 -

Rott

erd

am

A20/A

12 -

Gouda



Simulation results A20

• Increase of capacity and saturation flow (~100-150 veh/h)

• Negative side effect

• Lane-drop > advice towards right-hand lane > increased

interaction with onramp and offramp (with spillback)

• No considerable differences between advised and unadvised

drivers.

• Impacts of advice principles cannot be superimposed

• E.g. spillback advice principle alone: target lane is oversaturated



A67 Eindhoven

• Very high intensities

• Calibration A20 vs. A67

N2/Eindhoven: ~2500veh/h Geldrop: 1000-1500veh/h

2000-2500veh/h

2.5km

Parameter Description A20 A67

T Desired headway 1.2 s 0.89 s

a Max. acceleration 1.25 m/s2 1.56 m/s2

2500-3000veh/h



Changes for DLG

• Estimate current traffic state

• Recognize ‘fronts’ and assign speed (i.e. prediction)

t

x

vl

x0

t0 t

x

-v

x0

t0

Platoon Congestion tail

< 60 km/h

> 60 km/h< 2400 veh/h

< 2400



Preliminary results

• Reduction in travel time delay (-33%)

0 200 400 600 800 10000

0.2

0.4

0.6

0.8

1

Travel time delay [s]

Cu

mu

lative

dis

trib

utio

n

All vehicles over 30 runs

Base (179.9s)

All (121.4s)

Platoon (186.4s)

Cong. head (119.9s)

Rev. prio's (122.8s)



Outlook and challenges

• Effects of data delay

• For A20: 75s

• For A67: 180s (despite 75s NDW specification)

• (75s was used for the preliminary results)

• Improving accuracy

• False-positives; bad for confidence in system

• In-car filtering based on speed; not trivial

• Depends on data (aggregation, delay)

• Human factors

• Workload, compensation effects, safety



Thank you for your attention!

transport thursday 18 december 2014 - dynamic lane guidance

Technology

affordable positioning

lane level free flow

futuredynamic lane guidance

carrier phase bias

carrier phase windup

singlefrequency user

future impression

data delay1