Like Clockwork

John Ball, Senior Product Manager at SWARCO, discusses how Traffic Management Systems (TMS) can be utilised to further improve and enhance bus priority schemes to reduce journey times and maintain reliable bus services, as well as helping to reduce harmful emissions.

John Ball Senior Product Manager at SWARCO

By definition bus priority schemes aim to reduce journey times and improve the reliability of services for passengers. Equally important is the role they can play in reducing emissions. More use of buses and other public transport coupled with less use of private passenger vehicles can lead to a more efficient transport system, with improved traffic and environmental conditions for all. While there have been some concerns over the potential knock-on effect for other road users, with some predicting priority for buses would slow other traffic and cause greater levels of congestions, well-designed bus priority schemes are proving good for everyone, and allow more people to move more quickly even on busy routes.

Creating an effective bus priority scheme that reduces journey times, congestion and service reliability, that benefits all road users, is not as simple as increasing the number of bus lanes. Equally, there is not a one-sizefits-all solution. There are a number of tactics and strategies, including segregation, traffic signal control and bus stop upgrades, that can be utilised in combination to increase reliability and efficiency. Intelligent Transport Systems and solutions, such as Traffic Management Systems (TMS), can also play a key role.

TMS

Traffic Management Systems are a form of Urban Traffic Control (UTC) system that can be utilised to monitor and control urban traffic. TMS allows for better traffic performance from a road network by reducing delays to vehicles and the number of times they must stop. And can also be used to balance capacity within a traffic network, attract or deter traffic from specific routes or areas, prioritise specific vehicles such as public transport, arrange for queuing to occur in suitable, less busy parts of the network, and enhanced fault monitoring and maintenance of equipment.

What is important with any TMS is that operators can monitor and control all elements of the network, which is why SWARCO TMS is equipped with SCOOTview, a web-based graphical user interface enabling the user to ensure that appropriate control strategies are being implemented according to time of day or traffic conditions. The system supports a mixed approach to signal control; Fixed Time UTC (with or without SAPS), SCOOT, MOVA and remote monitoring. This enables the optimum strategy to be selected, supporting the need for efficient network performance, reduced congestion, and improved air quality.

TMS enables users to coordinate, control and monitor a region's signalised traffic intersections. SCOOTview brings together equipment status monitoring 'at a glance' and intuitive access to the full suite of tools, minimising the effort required to monitor system operation.

Priority Measures

There are multiple ways in which TMS can be used to support and further enhance bus priority. Segregation typically means dedicated bus lanes. In the context of bus priority, TMS can alter the timings and sometimes even the sequence of traffic lights to help buses pass through junctions with minimal delay.

Bus locations are reported to a backoffice system using GPS and wireless communications. The equipment to do this is typically integrated with the ticketing machine or system.

Predefined virtual detector locations can trigger a priority request when the bus reaches that position. The backoffice system sends a priority request message to TMS, using the Real Time Information Group (RTIG) T031 bus priority protocol that lets the system know that a bus is approaching and from what direction.

If a bus is approaching a set of traffic lights at green, TMS can be used for extensions to prevent the lights from changing until the bus has passed, which can significantly reduce delays. If the bus has already missed the green light, then TMS can be used for recall, returning the lights to green more quickly than usual. Priority is often only granted when a bus is running late, or if the request message is marked as being urgent. This mechanism allows TMS to intelligently manage conflicting requests from two or more buses approaching from different directions, with priority given to the bus that is running behind schedule. If both buses are late, priority is given to the bus that is running further behind.

Priority requests that TMS receives are fed into intelligent algorithms, such as SCOOT or

MOVA, that help to optimise traffic management, to provide and manage the recovery of the traffic network as and after buses pass through.

Derbyshire County Council is just one example of a local authority using this functionality of SWARCO TMS to help deliver its multi-million Bus Service Improvement Plan (BSIP) unveiled in 2022. Within the first three years of the BSIP, the majority of traffic signal junctions in Derbyshire will have automated bus priority, and by 2027 all signalled junctions in Derbyshire will have bus priority as ‘standard’.

Conclusion

There are several tactics, strategies and measures that can be utilised to implement bus priority schemes but they do not have to be dependent on additional bus lanes, redesigning road networks, undertaking major works or requiring capital investment. The smartest solution is found in the intelligent transportation systems which allow schemes to be easily rolled out at scale, as well as providing the flexibility for local authorities to prioritise the most urgent routes and ultimately resulting in a future proof solution that is cost effective to maintain. TMS is playing a key role in centralising bus priority schemes and helping to improve service reliability and journey times to the benefit of all road users.

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