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Evolution of LUMS on Queensland MotorwaysQueensland Department of Transport and Main Roads

Dr Miranda Blogg, Principal Engineer (Traffic)

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Presentation overview

• LUMS how-to guidelines• Device placement

• Gantry design

• Temporary traffic works

• LUMS projects• Complex geometry

• Automated responses

• National differences

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Introduction – QLD managed motorways

STREAMS

Motorways Operations

Incident Management System (SIMS)

Ramp signals

(HERO)

Lane use management

(LUMS)

DATA

Variable & enhanced messages (V/EVMS)

DetectorsWeather Station

CCTV

Motorways Incidents

RESP

ON

SE

DetectorsDetectors

CCTV

Automated speed Manual lane-use & speed Automated signal

Automated messages Manual messages

Manual actions (response plans)

Help PhonesCCTV

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Condition high traffic volumes

stationary or slow moving queue

high wind, rain, poor visibility or surface friction

Speed reduction

zone to a minimum of

70km/hr

within and immediately upstream of the queue - to

60km/hr

zone to a minimum of 40km/hr

Introduction – VSL algorithms

LUMS

High Flow Queue detection and protection

Weather

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Guidelines

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ITS placement guideline

all devices, with a focus on detectors & VSL

mainline motorway, with a focus at bottlenecks

managed motorway’s planning & design phase

illustrate importance of placement to improve VSL algorithm performance

step-by-step instructions by bottleneck type

When

Where

What

Why

How

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ITS placement guideline• Bottleneck types – I (surge), II (geometry), & III (weave);

off-ramp queues

• Band defined to accommodate civil/electrical constraints• Not all possible configurations can be described

Congestion Ahead

D2 D1D3DRepeater DRepeater

VSLControl VSLRecovery

Minimise (squeeze)spacing to bottleneck

<50m50 to 300m 0-25m 200m (min) - 400m max

Push out Drepeater spacing in basic sections Push out Drepeater spacing in basic sections

Direction of Flow

⟹

⟹

⟹

300m +

Known

bottleneck

Conform

ance B

and

6060

60

Conform

ance B

and

9090

90

8080

80

Mark known bottleneck locations

Place detectors immediately

upstream of the bottleneck

Place upstream “control” VSL in

the conformance range

Place downstream “recovery” VSL in the conformance

range

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ITS placement guideline• Guidelines have been applied to a number of design

projects: Gateway Motorway north PAC Motorway Bruce Highway Port of Brisbane Motorway Western Freeway

• Built projects have not applied the guidelines: Ipswich Motorway Gateway Motorway

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Gantry decision aide

+$500k NPV over 30 years

(SMEC 2010)

Accessible Gantriessafer for worker/traffic

< traffic management $$

Non-Accessible Gantries less intrusive structures < design/construct $$

Efforts to reduce $$ can reduce outcomes e.g.:• Use pole mounted VSL instead of LUMS – no lane control• Increase gantry spacing - less control and lower compliance

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Gantry decision aide• Hyder, together with TMR, have examined the selection and

design of gantries, considering opportunities for savings

• Flow chart tool developed to prompt designers to consider retrofitting existing structures collocating devices gantry super-spans to reduce barrier costs maintenance options deviations from standards

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Gantry decision aide

• Policies amended:• remove accessible gantry requirement

• remove “VSL only” on 3+ lanes gantry requirement

• allow for colocation of VSL/LC and VMS

• Allow for up to 200 m lateral separation of pole mounted signs

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LUMS for temporary works• Current advice:

Traffic Road and Use Management (TRUM) 7.6 Uses LUMS, supplemented by static signs

• Issues: No training – training focused on static signs; TRUM 7.6 not being

used. Increased coordination - contractors required to coordinate with

TMCs; contractors need more support from regions Long upstream signage distances - Due to the spacing of LUMS,

upstream speed reductions can be very long (>1km) Full statics required – no savings in time or effort; requires

multiple steps with TMC to set down and remove static signs

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LUMS for temporary works

• Objective of revised guidance: Reduce the physical extent of LUMS Reduce the requirement for static signage Reduce # of times the contractor communicates with the TMC

and the # of changes the TMC must make Provide a tool to assist contractors

• Tool options1. Uses LUMS instead of upstream statics

2. Uses LUMS to supplement statics

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LUMS for temporary works

• LUMS visibility and spacing = opportunities to deviate from static signage practice: single speed buffers (100 to 40 with a single 60) shorter distances from LUMS relative to works shorter physical tapers reduction in static signs - complementary within the works on one side

of the motorway # of TMC changes is reduced as there are no upstream statics

• Next steps – assess the risks associated with deviations from static sign practice

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LUMS projects

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Lane control in complex geometry

Type footer details here | 13 April 2023

• Lane control can be challenging in complex geometry

• operator closes an incident lane• a system generated response is only plausible for 1 in 4

scenarios (single or multi lane incidents) • all other generated responses result in the full closure of the

section

Gantry 1

Direction of Flow

⟹

⟹

90

Gantry 2

Gantry 3 Gantry 4

90

9090

90

9090

XX

XX

Gantry 1

Direction of Flow

⟹

⟹

40

Gantry 2

Gantry 3 Gantry 4

40

9090

90

9090

40

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Lane control in complex geometry

• Soft closure reduces some benefits - limits emergency vehicle access & protection of the incident vehicle

Type footer details here | 13 April 2023

Gantry 1

Direction of Flow

⟹

⟹

90

Gantry 2

Gantry 3 Gantry 4

90

9090

90

9090

XX

XX

Gantry 1

Direction of Flow

⟹

⟹

40

Gantry 2

Gantry 3 Gantry 4

40

9090

90

9090

40

Automated

Manual – flashing X/soft closure

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Lane control in complex geometry

• Lane control design advice: use on 3 or more lanes place gantry downstream of the merge and outside of the legibility

distance to limit the driver load/distraction place first gantry upstream of an off-ramp - during a full closure,

drivers have the ability to exit the facilities Note – the kerbside lane of a gantry with a downstream mainline

lane-drop is awkward – in theory should always display flashing X

Gantry 1

Direction of Flow

⟹

⟹

90

Gantry 2

Gantry 3 Gantry 4

90

9090

9090

90

9090

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Automated detection algorithms

• Queensland managed motorways funding is based on a full suite of treatments. The expected benefits are: increase in the travel speed (to a

minimum speed of 75km/hr) reduction in crashes (25%), and reduction in incident duration

(20%)

• These can’t be achieved without timely detection and responses

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Automated detection algorithmsCurrent VSL practice:

manual speed changes based on observed incidents

Initial trial of VSL algorithms: reduce detection time from 20 to 2 minutes increased detection – 50% more; typically shorter duration type

Others not yet measured: responsiveness - to changes beyond initial detection consistency – in the displayed speed response level of effort – reduction in workload imposed on operational staff

Future of VSL: automated detection with semi-automated response (e.g. an alarm)

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LUMS display

Flashing X = move to either lane

OR Upward arrow = exit at off-ramp

Left or right downwards arrows = move as directed OR Upward arrow = exit at off-ramp

Queensland

Other States

DRAFT

• AustRoad - concerted effort to harmonise practice

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Island closureexample

40 40 40

100 100 100

60 60

80 80

X

80

40

100

60

80

40

100

60

80

60

40 40

100 100 100

60

80 8080

40

100

60

80

40

100

60

80

60

Dire

ction

of F

low

XThis flashing X indicates that

motorists have a choice to merge left

or right. In this scenario which merge

arrow direction would be specified?

Left; Right or Left/Right?

Which merge

direction?

Queensland Flashing X’s Merge Arrows

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Multiple lane closures extending over an exit ramp.

Dire

ction

of F

low

⟹ ⟹ ⟹

90 90 40X

100 100 100

60

80 80

100 100 100

X

⟹ ⟹ ⟹

90 90 40X

100 100 100

90 90 60

80 80

100 100 100

X

X

Queensland Flashing X’s Merge Arrows

Exit is open to traffic

80

Combination of merge right arrow and exit left

arrow is confusing

GANTRY 1

GANTRY 3

GANTRY 2

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LUMS display

flashing X vs arrows benefits

easier to config the

device

easier for the

operator to use

more flexible for the driver

easier to test the system

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ConclusionsAct

Observe

Queensland maturing LUMS practicePlan

ActObserve

Reflect Plan

Act

Observe

ReflectPlan

Reflect

Where are we?• Guidelines (act) – have acted on

the need to provide design advice, but not yet able to observe operational outcomes

• Lane control (reflect) – being used but room for improvement

• Automated VSL (observe) – live traffic trials underway

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Thank you