Traffic management

Table of Contents

Appendix L Traffic Signal Techniques to Support Network Operation Planning Toolkit

The Signal Management Toolkit has been developed as part of research project NT1909: Signal management techniques to support network operations (Austroads 2015e). The purpose of the Toolkit is to assist road agencies in the identification and assessment of signal management techniques that will support the intent of the network operation plan (NOP). This guidance is particularly relevant to Stage 5 of the NOP process (development of traffic management, operation and improvement plans) and undertaking of a network fit assessment (NFA). Refer to Austroads (2016a) for description of the NOP process and NFA.

The Toolkit assists to assess the impact of different signal management techniques on various road user needs. Road user groups included are general traffic, freight, public transport, pedestrian and cyclist. The Toolkit assess impacts for road users in the direction or movement directly impacted by the treatment and road users travelling in the conflicting directions or movements.

The Toolkit broadly covers level-of-service needs of road users such as:

  • mobility (i.e. delay)
  • safety
  • access (i.e. level of restrictions to movements, for example banned movements at an intersection will degrade access).

Refer to Austroads (2015d) for details on the level of service needs for various the road users. Many traffic signal techniques impact not just mobility but also aspects of safety and access to get a better understanding of impacts and the trade-offs involved.

The Toolkit seeks to raise awareness of practitioners to potential impacts of proposed techniques that may not have otherwise been considered as part of the decision-making process. It will allow practitioners to demonstrate the alignment of the technique with the NOP and thereby assist in justifying its use to other stakeholders.

The Toolkit is primarily intended for planning purposes, not for detailed operations. It does not provide detailed impact assessments for each site-specific application of a technique. Those techniques with a wide range of impacts across applications may require further investigation to determine the likely impacts for a specific context. The conclusions of the NFA should be sensitive to the potential ranges of impacts.

The Toolkit is available in Excel format (downloadable from the Austroads website) and an abbreviated static version is provided in Table L 2.

The toolkit is essentially a table of likely impacts of various traffic signal techniques. The impact is rated from ‘significant positive impact’ to ‘significant negative impact’ as shown in Table L 1.

The term impact is defined as a change in level-of-service relative to a baseline, wherein the baseline assumes:

  • signalised intersection (i.e. all movements protected) with no/equal priorities.
  • pedestrian crossings are provided, i.e. fully protected parallel walk
  • cyclists are allowed to use the pedestrian phase but need to dismount.

Table L 1: Label for impacts of signal management techniques

ImpactLabel used in the Toolkit (Table L 2)
Significant positive impact+ + +
Medium positive impact+ +
Low positive impact+
No impact0
Low negative impact-
Medium negative impact- -
Significant negative impact- - -

The impact assessment in Table L 2 is indicative only, and includes a range where appropriate, depending on different applications. Real impacts will vary depending on site characteristics and other factors, which should be considered in the assessment process.

Also, more than one technique may be implemented at an intersection concurrently; however, this assessment only considers impacts separately. Combined impacts may need to be investigated further.

Table L 2: Impact assessment for signal management techniques (impacts are indicative only)

NameImpacts for road users travelling in direction of treatmentImpacts for road users travelling in conflicting directions to the treatment
OutcomePrivate motoristTramBusPedestrianCyclistFreightOutcomePrivate motoristTramBusPedestrianCyclistFreight
BaselineMobility 0 0 0 0 0 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 0 0 0 Safety 0 0 0 0 0 0
Access 0 0 0 0 0 0 Access 0 0 0 0 0 0
Techniques that support public transport priority
Green extension/
phase extension
Mobility + + to ++ + to ++ 0 + + Mobility - - - - - -
Recall/red truncation or early green/priority green/phase early-startMobility 0 to + + to +++ + to +++ 0 to + 0 to + 0 to + Mobility - - - - to 0 - to 0 -
Safety 0 0 to + 0 to + 0 0 0 Safety 0 0 0 0 0 0
Additional phase in signal cycle to clear queues in front of buses/tramsMobility + + to +++ + to +++ + + + Mobility - - - - - -
Safety 0 0 to + 0 to + 0 0 0 Safety 0 0 0 0 0 0
Priority phase sequencesMobility Varies + / - ++ to +++ ++ to +++ Varies + / - Varies + / - Varies + / - Mobility -- to - -- to - -- to - -- to - -- to - -- to -
Safety 0 0 to + 0 to + 0 0 0 Safety 0 0 0 0 0 0
Phase suppression (of conflicting movements)Mobility 0 to ++ + to +++ + to +++ 0 to ++ 0 to ++ 0 to ++ Mobility --- to -- -- to 0 -- to 0 --- to -- --- to -- --- to --
Safety 0 0 to + 0 to + 0 0 0 Safety 0 0 0 - to 0 - to 0 0
Access - to 0 0 to + 0 to + - to 0 - to 0 - to 0 Access -- to 0 -- to 0 -- to 0 -- to 0 -- to 0 -- to 0
Public transport priority phase with dedicated lanesMobility --- to - +++ +++ - to 0 - to 0 --- to - Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety 0 + + 0 0 0 Safety 0 0 0 0 0 0
Public transport priority phase with queue-jump lanesMobility - ++ to +++ ++ to +++ - to 0 - - Mobility - - - - - -
Safety 0 0 to + 0 to + 0 0 0 Safety 0 0 0 0 0 0
Priority movement repetition in cycleMobility 0 to + + to ++ + to ++ 0 to + 0 to + 0 to + Mobility -- to - -- to - -- to - -- to - -- to - -- to -
Reduced cycle timeMobility - to -- + + 0 to + 0 to + - to -- Mobility - - - 0 to + 0 to + -
Gating to an area for queue managementMobility Varies + / - + to ++ + to ++ 0 0 Varies + / - Mobility Varies + / - Varies + / - Varies + / - 0 0 Varies + / -
Techniques that support freight priority
Longer signal cycle times (higher minimum cycle times)Mobility 0 to + - to 0 - to 0 - to 0 0 to + + Mobility -- to 0 -- to 0 -- to 0 -- to 0 -- to 0 -- to 0
Safety 0 to + 0 0 0 0 + Safety 0 0 0 0 0 0
Coordinating signal offsets for heavy vehiclesMobility - to 0 0 to + 0 to + 0 0 + to ++ Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety - to 0 0 0 0 0 + Safety 0 0 0 0 0 0
Green extension/dwell phase extension/early startMobility 0 to + 0 to + 0 to + 0 to + + + to +++ Mobility - - - - - - to 0
Safety 0 0 0 0 0 + to ++ Safety 0 to + 0 to + 0 to + + to ++ + to ++ 0 to +
Techniques that support pedestrian priority
Exclusive signal phase for pedestriansMobility -- to - -- to - -- to - Varies + / - -- to - -- to - Mobility -- to - -- to - -- to - Varies + / - -- to 0 -- to -
Safety 0 to + 0 to + 0 to + + to +++ 0 to + 0 to + Safety 0 to + 0 to + 0 to + + to +++ 0 to + 0 to +
Exclusive ‘scramble crossing’ or ‘Barnes dance’ phaseMobility -- to - -- to - -- to - + -- to - -- to - Mobility -- to - -- to - -- to - + -- to - -- to -
Safety 0 to + 0 to + 0 to + + to +++ 0 to + 0 to + Safety 0 to + 0 to + 0 to + + to +++ 0 to + 0 to +
Access 0 0 0 ++ 0 0 Access 0 0 0 ++ 0 0
Double/half cyclingMobility - 0 to + 0 to + + + - Mobility - to 0 - to 0 - to 0 0 to + - to 0 - to 0
Safety 0 0 0 0 to + 0 0 Safety 0 0 0 0 to + 0 0
Dwell on red for all users, or dwell on walk (green) for pedestriansMobility -- to - -- to - -- to - 0 to +++ Varies + / - -- to - Mobility -- to - -- to - -- to - 0 to +++ Varies + / - -- to -
Safety 0 to + 0 to + 0 to + 0 to ++ 0 to + 0 to + Safety 0 to + 0 to + 0 to + 0 to ++ 0 to + 0 to +
Extended clearance intervalsMobility - to 0 - to 0 - to 0 0 to ++ 0 to + - to 0 Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety 0 0 0 + to ++ 0 to + 0 Safety 0 0 0 0 0 0
Extended walk/stretch walk/rest in walkMobility - to 0 - to 0 - to 0 + to ++ 0 to + - to 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 Varies + / - 0 to + 0 Safety 0 0 0 0 0 0
Reduced cycle lengthsMobility - to 0 Varies + / - Varies + / - + + - to 0 Mobility - - - + + -
Safety 0 0 0 + + 0 Safety 0 0 0 + + 0
Pedestrian detection and variable green man intervalMobility - to 0 - to 0 - to 0 + - to 0 - to 0 Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety 0 0 0 + 0 0 Safety 0 0 0 0 0 0
Fixed demandMobility - to 0 - to 0 - to 0 + Varies + / - - to 0 Mobility - to 0 - to 0 - to 0 + Varies + / - - to 0
Safety 0 0 0 + + 0 Safety 0 0 0 + + 0
Puffin crossingMobility Varies + / - Varies + / - Varies + / - Varies + / - Varies + / - Varies + / - Mobility Varies + / - Varies + / - Varies + / - 0 Varies + / - Varies + / -
Safety 0 0 0 0 to ++ 0 0 Safety 0 0 0 0 0 0
Isolated traffic controls at areas with high pedestrian demandMobility - to 0 - to 0 - to 0 + Varies + / - - to 0 Mobility - to 0 - to 0 - to 0 + Varies + / - - to 0
Safety - to 0 - to 0 - to 0 0 - to 0 - to 0 Safety - to 0 - to 0 - to 0 0 - to 0 - to 0
Pedestrian countdown timersMobility 0 0 0 0 to + 0 to + 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 Varies + / - Varies + / - 0 Safety 0 0 0 0 0 0
Reintroduction of pedestrian walkMobility - to 0 - to 0 - to 0 + to ++ - to 0 - to 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 0 to + 0 0 Safety 0 0 0 0 0 0
Techniques that support cyclist priority
Late start for vehicles (early start/leading interval for cyclists)Mobility - - - - to 0 + - Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety 0 0 0 0 + to ++ 0 Safety 0 0 0 0 0 0
Fully protected parallel crossing for cyclists at shared path crossingMobility 0 0 0 0 + 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 - to 0 + 0 Safety 0 0 0 0 0 0
Extended clearance intervalsMobility 0 to + 0 to + 0 to + 0 to + - 0 to + Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety 0 0 0 0 + 0 Safety 0 0 0 0 0 0
Longer green time for cyclists at shared path crossingsMobility 0 0 0 0 + 0 Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Exclusive signal phase for cyclistsMobility -- to 0 -- to 0 -- to 0 -- to 0 ++ -- to 0 Mobility -- to 0 -- to 0 -- to 0 -- to 0 -- to 0 -- to 0
Safety 0 to + 0 to + 0 to + 0 to + ++ 0 to + Safety 0 to + 0 to + 0 to + 0 to + 0 to + 0 to +
Activation of green signal phase when cyclists are detectedMobility - to 0 - to 0 - to 0 - to 0 + - to 0 Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety 0 0 0 0 + 0 Safety 0 0 0 0 0 0
Signal coordination for cyclist priorityMobility - - to 0 - to 0 0 ++ - Mobility - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Safety - to 0 - to 0 - to 0 0 + - to 0 Safety 0 0 0 0 0 0
Arterial reversionMobility 0 0 0 0 0 to + 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 0 0 to + 0 Safety 0 0 0 0 0 0
Cyclist bypass lanes at T‑intersectionsMobility 0 0 0 0 + 0 Mobility 0 0 0 0 0 0
Safety 0 0 0 0 - to 0 0 Safety 0 0 0 0 0 0
Mid-block crossing signals for cyclistsMobility N/A N/A N/A 0 + N/AMobility 0 0 0 0 0 0
Mid-block crossing signals for cyclistsSafety N/A N/A N/A - to 0 0 to + N/ASafety 0 0 0 0 0 0
Access N/A N/A N/A 0 + N/A Access 0 0 0 0 0 0
Techniques that support general traffic priority
Improved signal coordination/ progressionMobility + to +++ 0 to + 0 to ++ - to 0 Varies + / - + to ++ Mobility - to 0 - to 0 - to 0 0 0 - to 0
Safety 0 to + 0 to + 0 to + 0 0 to + 0 to + Safety 0 0 0 0 0 0
Banned right‑turnsMobility + to ++ + to ++ + to ++ 0 to + 0 to + + to ++ Mobility 0 to + 0 to + 0 to + 0 0 0 to +
Safety 0 0 0 0 to + 0 to + 0 Safety 0 0 0 0 0 0
Access - - - 0 0 - Access 0 0 0 0 0 0
Skip right-turns every second cycle (peak times)Mobility + + + 0 to + 0 to + + Mobility 0 to + 0 to + 0 to + 0 to + 0 to + 0 to +
Safety - to 0 - to 0 - to 0 - to 0 - to 0 - to 0 Safety - to 0 - to 0 - to 0 - to 0 - to 0 - to 0
Access - - - 0 0 - Access 0 0 0 0 0 0
Maximum time transfer/stealingMobility + + + 0 to + + + Mobility Varies + / - Varies + / - Varies + / - 0 Varies + / - Varies + / -
Gating to an areaMobility Varies + / - Varies + / - Varies + / - 0 to + Varies + / - Varies + / - Mobility Varies + / - Varies + / - Varies + / - 0 Varies + / - Varies + / -
Safety 0 0 0 0 to + 0 0 Safety 0 0 0 0 0 0
SCATS Incremental Split Selection and Variation Routine 83 (for congestion management)Mobility 0 to + 0 to + 0 to + 0 to + 0 to + 0 to + Mobility Varies + / - Varies + / - Varies + / - 0 0 Varies + / -
Pedestrian parallel walkMobility + + + + + + Mobility 0 to + 0 to + 0 to + 0 to + 0 to + 0 to +
Safety - - to 0 - to 0 - 0 - to 0 Safety 0 0 0 0 0 0
Late start for vehicles (early start/leading interval for pedestrians) – partially protected parallel walkMobility 0 to + 0 to + 0 to + 0 to + 0 to + 0 to + Mobility 0 to + 0 to + 0 to + 0 to + 0 to + 0 to +
Safety - to 0 - to 0 - to 0 - to 0 - to 0 - to 0 Safety 0 0 0 0 0 0
Pelican crossingMobilityN/A N/A N/A 0 0 to + N/A Mobility 0 to + 0 to + 0 to + 0 0 to + 0 to +
Safety N/A N/A N/A - - to 0 N/A Safety - - - - - -
Two-staged crossing at wide intersectionsMobility + to ++ + to ++ + to ++ - to -- Varies + / - + to ++ Mobility + to ++ + to ++ + to ++ 0 0 to ++ + to ++
Safety 0 0 0 - 0 0 Safety 0 0 0 0 0 0

Legend:
positive and positive/neutral = green
neutral = amber
negative and negative/neutral = red
negative to positive range = grey
N/A means not applicable.