Paul Welsh MBCS CITP sheds light on intelligent transportation systems (ITS) and its many forms, used to run the services that keep the transport networks running smoothly as well as make life easier for drivers in their own vehicles.
There are two strands to the systems and services in use, the in-vehicle services, which many are familiar with without realising their origin and functionality, and the network services implemented and managed by the transportation services and Highway Authorities, unseen and largely unknown - because they work.
In the UK the developments started in the 60s when computers (Ferranti Argus, DEC PDPs and GEC 4080s) became less expensive and a transportation network model tool (TRANSYT) was developed by the Transportation Research Laboratory (Crowthorn), which could be used to optimise the traffic signal timings for an area based on measured traffic flows, journey times and traffic signal designs.
The two developments made it possible to control traffic signals from a central processor with timings changing to suit the time of day. The first trial took place in West London, followed by a large scale trial in Glasgow.
The rigorous assessment clearly showed that a 12 per cent reduction in delays at the traffic signals could be delivered by what became known as UTC - Urban Traffic Control. The success led to the government agreeing to an expansion to many cities in the UK.
Data transmission was by BT circuits running at a massive 300 Baud! With the line quality available then that was all that could be achieved without getting too many drop-outs. Elsewhere developments were also taking place, principally in the Far East / Australasia; America tended to lag for a long time because of a lesser need.
Greater processing power
In the late 70s the next key development enabled by the availability of greater processing power was the adoption of ‘real time’ (second by second) signal optimisation.
Fixed time systems do provide a real benefit, but the benefit s eroded by about 3 per cent/annum because of changes in traffic patterns. Real time systems track temporary and permanent changes with a much reduced loss of efficacy. In Australasia SCATS and in the UK SCOOT were the names adopted for the sets of algorithms.
Both produce a reduction in traffic signal delay of 17 per cent, but by different methods. Each has its strengths and weaknesses but overall is very cost effective, giving a typical ROR of nine to 15 months depending on how benefits are calculated. Interestingly as both have been further developed there has been a degree of convergence.
Changing to real time required a greater data rate, a jump to 1,200 Baud! Even this caused problems, for example when bearer circuits were being used between Coventry and Birmingham with eight transmissions time multiplexed on one pair of circuits, the dropout rate was so bad that junction control could not be maintained.
Eventually, after many complaints to BT, it emerged that they were testing data lines with a moving coil galvanometer and this was in the early 80s! Once the problem was explained to them they went away and sorted it.
In parallel with developments on signal control came the need to display signs on motorways, optimise car park occupancy and other traffic related functions, each of which initially was developed as entirely separate systems, which resulted in control desks with multiple terminals, user interfaces and cramped desks. The next step was the recognition that the systems were complimentary, leading to the UTMC (Urban Traffic Management & Control) development programme. For the UK this is now the norm.
Systems owned by several organisations local authorities, bus operators, car park operators and others, are aggregated into one super system to their mutual benefit with a saving on infrastructure and the development of additional functions at no or minimal cost.
For example, in Glasgow the detectors on the exit to a car park are used to determine the green time of the signals down the road and to monitor for the surge in traffic after an event so that the event management plans can be automatically triggered.
In Kent CCTV ANPR (Automatic Number Plate Reader) systems owned by Kent, the Highways Agency and the police can be aggregated to derive current journey time measurements. (The data protection issues are addressed by anonymising the data using a method that cannot be reverse engineered). The methodology is now of significant interest in other European countries.
The latest development is enabled by the Highways Agency (HA) policy of ‘managed motorways’ where there is cooperative management between HA and other network management systems.
For example, to avoid problems on the M42 such as those that occurred during the Crufts dog show several years ago, the HA M42 system, Solihull UTMC and NEC systems cooperate to manage traffic arriving for an event. On a bigger scale the systems in the West Midlands County form a super UTMC system with a county HQ, as well as local control centres.
It provides transportation services to 2.5M people plus commuters over an area of 2,500sq km. During an emergency the whole network can be controlled from any location so if a control centre is inaccessible due to congestion control is not lost due to lack of staff. The system architecture harnesses local knowledge as well as the benefit of the macro system when it is needed.
One key driver was the EC who recognised a need for both improvement in transportation management and a desire to have cross border standardisation.
A series of transportation frameworks were set up. Each of these had specific aims and international consortia had to bid to provide projects that conformed to the aims of the framework. In reality the EC grant only paid for the EC overheads, but did open doors to other grants that could pay for new transportation services.
Much of the benefit of the frameworks came from working with engineers from other countries both within the consortia and from the ‘concertation’ meeting where all projects in a framework came together in Brussels to share ideas.
Having several hundred very clever people in one place for formal and informal sessions proved a hot house for developing ideas. The days were 12-16 hours long, discussions sometimes heated, but intellectually stimulating.
Relevance to other IT areas
Two products of the EC work that are translatable to other areas of ICT are a rigorous user needs analysis methodology - KAREN and the development of data objects - DATEX, to enable valid intersystem data transfer.
This was extended in the UK as a necessary part of the UTMC project and is now being extended in DATEX III. Proper user needs analysis promotes a right-first-time delivery and can make significant savings in a project.
The problem lies in persuading a customer that it is money well spent, because they believe they know what is required. An example of how this is untrue was amply demonstrated in Gothenburg.
The public transport authority ran a survey to find out what travellers wanted in improvements to their bus and tram services. Management ran a sweepstake on who would identify the most requirements in the top ten. The winner got two correct!
New tech developments
One EC project was the forerunner for equipment now being fitted as an optional extra to top end vehicles. PROMETHIUS resulted in two heavily modified Jaguar cars. One could manage its speed by monitoring the distance to the car in front and the speed, up to a set maximum.
The more complex one was interesting to ride in as a passenger on the open road. The driver sat there with feet off the pedals and hands on his knees as the car drove itself. The processing power in the boot needed an extra alternator to run it as well as the radar and TV cameras.
Image analysis was used to ensure that the car following the carriageway markings and radar was used to maintain a safe distance from the car in front by controlling the brakes and throttle. Out of this work have come adaptive cruise control, reversing aids, lane deviation warnings, collision avoidance and self parking, which are all now available on some cars.
Another EC project was QUARTET, followed by QUARTET+. One product of this, now in its fourth generation, provides live information on travel in the Midlands.
Data is automatically collected from traffic control centres from Wolverhampton to Leicester, from the rail services, motorways and police across two counties. This is just one example of what is available around the world from Paris and Athens to San Diego.
Systems like these are dependant on the infrastructure that is responsible for managing the transportation services for their information. This note is just an introduction to what has become a widespread service which could not exist without IT. How wide is shown by the annual ITS World Congress which rotates between the Americas, Europe and Australasia.
There 4 to 500 papers are presented to between 6,500 and 9,000 delegates. It is also significant that ITS is now an engineering dicipline in its own right. People seeking to become acredited as Chartered or Incorporated Engineers may offer ITS as their speciality with the Chartered Institute of Highways and Transportation.
Follow a delivery trip for goods manufactured in south Birmingham and required at a factory north of Paris on a just-in-time basis.
After loading is complete the driver logs this on the on board unit (OBU) and headquarters notify the customer of the current ETA based on traffic conditions. The trucking company subscribes to a service that analyses moving vehicle data from users / data providers such as Eddie Stobart, M&S, National Coaches and others.
The current location of contributing vehicles is automatically collected and analysed to derive a network condition model that is transmitted to subscribers both in their vehicles and to their management systems, together with recommendations for alternative routes when there are network delays.
Passing onto the highway network the lorry is initially in the control area managed by the Solihull UTMC, which extends as far as the M42. There it enters the Active Traffic Management system controlled from the Highways Agency’s Quinton Regional Control Centre. Continuing south on the M40 motorway control eventually passes to South Mimms, which controls the M25 as well.
Part way down the M40 on board sensors alert headquarters to a tyre problem - it is overheating and could burst. The driver is asked to stop at the Silverstone services via the OBU, where he is met by a tyre service vehicle. Changing the wheel costs half an hour’s travel time but avoided the two hour delay which would have been experienced if the tyre had burst on the motorway.
In addition, because the tyre was new and hopefully can be repaired and probably re-treaded twice, there is a potential saving of at least a thousand pounds in operational costs. Headquarters update the customer with a revised ETA and revise the channel tunnel crossing booking once the driver notifies that he is on his way after the tyre change.
The Dartford crossings - tunnel and bridge have their own system. Leaving the M25 south east on the M2 the lorry eventually turns off to the channel crossing loading point at Ashford. The extent of the tunnel monitoring is well documented including vehicle location, CCTV, smoke detection and so on.
Once detrained at Coquelles in France the lorry continues
south on the E15 now on a route managed by a French TEN (Trans European Network) system. The customer is regularly updated with the ETA, specifically if there is any additional delay. Part way down the E15 the OBU alerts the driver to the fact that he has now been assigned a return load. The driver can check the details when it is safe to do so.
Arriving at the customer’s factory the driver logs arrival on the OBU, thereby ensuring that if the customer delays offloading any delay cannot be used as grounds for penalties under the just-in-time contract. After offloading the lorry proceeds to an overnight stop and, in the morning, to the return load supplier before returning to the UK to deliver the return load.
Throughout both the out and return trips there are ITS systems supporting the driver, helping to make the whole trip less stressful and convenient, or as the Highways Agency strapline reads - ‘Safe Roads, Reliable Journeys, Informed Travellers.’