The iBus project

In common with many world-class cities London faces transport and traffic challenges. London needs to move its workforce and visitors and respond to growth and demographic changes fuelled by the success of the city. London’s bus network, one of the largest and most comprehensive urban transport systems in the world, is facing up to these challenges with a significant investment in a new AVL, radio and RTPI platform know as ‘iBus’ – a key part of the Mayor’s Transport Strategy.

Scope

To get a feel for the size of the London bus network compare it with the London Underground network with its prescribed 12-line, 275-station system. London’s bus network however has 700 routes and 17,500 bus stops operating on roads in a City that has developed over 700 years. It has to deal with daily road closures, accidents and incidents and still provide an essential service to London’s population.

The number of people using buses in London is at its highest level since 1968 with 6.3 million journeys made every weekday compared with just under 4 million Underground journeys. And the number of bus passengers, routes and buses is forecast to increase – to support organic growth and to accommodate short-term programmes, for example the 2012 Olympics.

Challenges

The challenges involved in keeping so many buses moving and co-ordinated, as well as ensuring passengers have access to the right information at the right time demands innovative solutions.

London Buses is the name given to the part of TfL’s ‘Surface Transport’ division that operate the network. The bus fleet of just over 8,200 buses is managed by independently-owned bus operators. Only one of these – East Thames Buses – is owned by TfL, the rest being a mix of private and publicly-owned companies operating between and one and 13,000+ buses.

London Buses operates the largest bus communications, tracking and passenger-information system in the world. A beacon based AVL system is currently in use, supplying location data to a central control-centre feeding 2,000 on-street ‘Countdown’ signs providing real-time forecast bus arrival time information.

The Mayor’s Transport Strategy saw buses as a fast and comparatively cheap way of providing additional capacity to London’s transport network, and in 2003 it was recognised that the current systems would not meet this need. The cornerstone to the current system is a Band III Radio system that was originally designed for 5,000–6,000 users, for voice only. The system had been in place for some 19 years and obtaining spares was already becoming an issue. So with potential growth to more than 9000 buses by 2010 and over half a million voice radio calls every month forecast to rise further, the scalability of the existing system together with the obsolescence of the equipment demanded a new solution that would not only address the immediate issues being faced but provide a scalable future-proof platform for London’s growth.

On a daily basis London’s bus network is specified by TfL and delivered by Bus Operators who tender to run services under contract over each route. Each contract is based on agreed mileage to be run per route, together with a passenger waiting time measure and other performance standards to ensure a reliable service for London’s travelling public. For example, in central London buses are largely run on a frequency basis where buses are contracted to appear at set time intervals rather than at adhering to a given timetable.

This method of providing service on a ‘frequency’ basis has been very popular and has made the roadside RTPI Countdown signs a real friend to the travelling public.

Requirements

Any replacement system therefore had to provide:

• Superior emergency response for CentreComm – TfL’s centralised bus control centre
• ‘Code Red’ voice radio from buses to CentreComm
• Direct communication from CentreComm to all buses, groups of buses or specific bus drivers
• Direct communication to bus passengers
• A bus operator ‘Service Control’ facility, including voice services to enable bus operators to adhere to their contracted service provision
• Performance measurement for both TfL and bus operators
• Passenger information
• More accurate feeds to Countdown signs
• Bus priority as part of selective vehicle detection at junctions
• Interface with existing ticketing infrastructure
• Security, safety, enforcement and monitoring support.

As well as improving existing functionality the opportunity was taken to increase the scope to provide:

• On-bus audio and visual next stop and ‘alight here for’ information
• Low bridge alarms for drivers
• Headway information for drivers to regulate bus service
• Pre-recorded on-bus messaging to enable drivers to communicate with passengers in a standard way
• Provide a reporting data-store for bus journey/traffic flow information

Procurement

In 2004 TfL tendered for a solution that satisfied these objectives and finally awarded the contract in April 2005 to Siemens VDO.

From the outset, TfL’s strategy was to contract for a complete system, with the development, supply and system operation being sourced from one prime contractor. However, the project has not been completely outsourced – the ownership of the system and all of its assets remains with TfL, who also retain control of data sources, business applications/tools and interfaces to internal and external clients, TfL Stakeholders, bus operators and the public.

To enable this, TfL’s Technical Service Group (TSG) have built a team to specify, test, commission and accept the solution and ensure its smooth implementation into the London network.

Solution design

The technical solution consists of a development of Siemens VICOS-LIO system control application together with their IBISplus technology that is also being enhanced to match TfL’s specification. The contracted solution consists of:

• Vehicle Location technology combining GPS positioning with algorithms specified by TfL using the odometer and direction
• An integrated Mid-Band radio system for voice and data
• Wireless-Lan installations at each garage to transfer data to/from buses
• Radio coverage to provide near 100% cover over all of London’s bus network
• On-board audio and visual ‘next stop’ systems for every bus
• Integration with existing Countdown system
• A ten-year service contract.

As well as replacing the ageing technology and providing a platform for growth the solution provides:

• An element of system ‘intelligence’ to reduce reliance on driver login and other potential bus identification problems
• Advanced system-wide monitoring, diagnostic and reporting tools
• A wealth of journey-time data
• Implementation of standards and market proven equipment to reduce supplier lock-in
• Expandable on-bus platform for future applications, for example real-time monitoring of CCTV cameras
• Improved quality of data within the TfL organisation.

Prototype passenger information

In the broadest sense testing has been underway since the winter of 2005/6 where five buses on route 149 demonstrated the capabilities of the new AVL system with a limited trial of the On-Bus audio and visual systems.

Passenger research was carried out with a wide range of user groups – regular, new and infrequent users, passengers with disabilities, school children and users who do not have English as their first language.

The results were very positive –91% of respondents said the new system would be beneficial – a point summed by Jane Wilmot a hearing-impaired bus user who commented: “Buses used to be for people who knew the way”. The tests enabled TfL to refine the policies that dictate when and how announcements would be made in the final system and gave valuable feedback from the future users of the system.

User comments included:

“Emma Hignett (voice of bus announcements) speaks with very clear diction and the right level of authority which will give passengers confidence.”

Visually impaired passenger

“I’m actually really looking forward to having this system on the buses….it would make my life a lot easier. I would feel more relaxed.”

Hearing impaired passenger

The remaining development has been completed on-schedule to enable location accuracy and system trials to commence in autumn 2006 and early results are encouraging.

Risks in development

For a system of this size there are many potential risks to overcome but probably the largest single technology risk was the use of GPS in such a large conurbation where GPS was expected to suffer from poor reception, outages and the multi-path effect. This was especially important where the requirement is to identify bus location to within +_ 5m for 95% of the time while on-route. This tight tolerance will enable the tracking and on-board RTPI systems to work properly announcing the right stop in a timely manner. The TSG team took extensive advice from other bodies including a research trial undertaken by PA Technology in conjunction with the University of Glamorgan, the experience of RATP Paris together with that of London Ambulance/ComCab. The conclusions were that GPS coverage is not a perfect model, but when supplemented by other sources like wheel rotation the system could achieve the required accuracy.

The backbone of the solution is a communications network that overcomes the shortcomings of the existing system and provides:

• Improved Voice Radio coverage and additional capacity with a Grade of Service increased from <70% to better than 90%
• Garages and central locations linked via a third party provided Wide Area Network (WAN) with Virtual Private Network (VPN)
• AVL data and sign data carried over commercial mobile data service
• Higher capacity data to and from bus.

Rollout

Outside of the technical challenges, the roll-out is logistically daunting as in addition to the large numbers of on-bus and garage installations, the existing business has to work and perform while iBus is being implemented. To mitigate this, the roll-out plan is being implemented route by route with all the routes served by a single garage being installed in one phase. Technically the iBus solution has been designed to be capable of being rolled-out from one bus, garage, route to another in such away that does not require reconfiguration or manual intervention as a new route is introduced. The initial phase of the roll-out extends the system trials into a single ‘first garage’ trial where the entire system including the training AVL and Radio technology will be tested on the first few routes. When concluded two installation centres will enable up to 24 buses per night to be converted to iBus meaning that the entire fleet should be converted by 2009.