Effective road and traffic management

Written evidence from Urban Traffic Management & Control (UTMC) (ETM 05)

1. Executive summary

1.1 Effective road and traffic management involves a complex deployment of policy, physical design, signage, licensing and – increasingly – technology systems. While fixed aspects (such as junction design) provide the basis for management, only technology can provide responsive management of a day to day (and sometimes minute to minute) basis.

1.2 Technology can be complex, risky and expensive, and much effort has been put by both public and private sectors into minimising these issues. However the pace of change means that this needs continual review and guidance.

1.3 DfT has been helpful in this area for many years. We believe that there are areas where central Government could and should continue to provide leadership and guidance, especially in ensuring that the various organisations involved – and the systems they use – work effectively together.

2. About the UDG

2.1 The UTMC Development Group (UDG) is a community body [1] which brings together local highways authorities, the Highways Agency, the systems industry and the service sector. It was formed in 2003 to bring to market the output of the DfT-led Urban Traffic Management and Control (UTMC) research programme (1997-2003).

2.2 The UDG is led by an elected Management Group, supported by a professional Secretariat; resources are a mix of central funding (previously provided by DfT, currently by HA), membership subscriptions, and income from the UTMC Annual Conference which has run since 1997.

2.3 The core of UTMC is a set of open technical specifications, designed to help highways authorities specify their needs and to help industry deliver effective solutions. The kinds of system that it covers include the following (though more are being added all the time):

· Monitoring systems for air quality, CCTV images, etc

· Control systems for traffic signals, barriers, etc

· Variable message signs, for car park information, journey times, warning messages etc

· Strategic systems for network coordination, incident management etc

· Links to public transport operations, for bus priority etc

· Public information websites

2.4 By using UTMC specifications, traffic managers can competitively procure products from multiple suppliers, and integrate them reasonably easily and with minimal cost and risk.

2.5 UTMC is policy neutral, and designed as a "toolkit", enabling users to build on no more than they need, and at their own pace. Specifications are primarily derived from system developers, but subject to open public consultation prior to adoption, so they are kept both practical and market neutral.

2.6 UTMC specifications are not mandatory "standards", but practical consensus recommendations. Authorities and suppliers are free to adopt non-UTMC solutions if they believe them to provide better value for money. This imposes a strong discipline on the UDG to stay relevant and focussed.

2.7 As policy challenges develop and technology opportunities continue to diversify, the UDG works increasingly in collaboration with other specifications groups, both in the UK and internationally. Our commitment is to act as a "self-help" group for the industry, to enable traffic managers across the country to do their job better, cheaper and more consistently.

2.8 UTMC became "mainstream" in the UK urban context from about 2006; there are now something like 100 implementations, including some outside the UK. It has recently benefited from a major boost with the active engagement of the Highways Agency, which is now looking to adopt/adapt UTMC to the interurban context.

2.9 Our evidence to the Committee concerns (and is limited to) evidence on areas where technology systems can help, or hinder, the management of road traffic.

3. Factual evidence

Prevalence and impact of traffic congestion and likely future trends

3.1 The UDG’s starting point is that there will continue to be traffic congestion events for the foreseeable future, and that the negative effects of these can be mitigated by active management.

3.2 A general trend to higher traffic levels will of course affect the prevalence of congestion, in much the same way that climate change affects weather events. The focus on traffic managers locally is to mitigate this trend by appropriate interventions, keeping congestion to (hopefully) acceptable levels.

3.3 Congestion "events" can occur for many different reasons: traffic accidents, road layout strictures, popular cultural events or just excessive traffic flow. These different congestion contexts have their own distinct dynamics.

3.4 Good management can pre-empt the occurrence and mitigate the impacts of congestion events. For instance:

· Accidents can be managed by activating diversion routes, speeding up access by emergency vehicles etc, thus reducing secondary accidents

· Junctions can be managed by monitoring the approaching traffic and selecting "strategies" for balancing green time, pedestrian phases etc

3.5 So, the effectiveness of management will affect the frequency and impact of congestion events that actually occur.

Government and local authority intervention

3.6 The different types of congestion normally call for different responses. Different authorities may choose to intervene in different ways, either for local policy reasons or simply because the nature of the networks differs.

3.7 Some interventions are strategic and have effect over a wide area and a long period of time, such as modal shift mechanisms (improved public transport, better pedestrian facilities, more cycle parking etc). Some may be described as pre-emptive – for instance, when planning a new development, the transport layout is also re-planned.

3.8 Technology systems such as those based on UTMC tend to be used for tactical management, ie for minute-to-minute or hour-to-hour changes.

3.9 Authority interventions are under continual review and evolution, to create greater understanding, coverage and coherence in managing the road network. For instance, the HA Integrated Network Management (INM) Programme consists of a set of technology Proof Of Concept projects developing, installing and making operational UTMC Common Databases. The planned UTMC-based technical platform provides facilities, supported by operational and technical processes, that join up HA traffic control and management systems to each other and those of neighbouring LHA UTMC based traffic systems and are readily compatible with many suppliers systems enabling greater integration, innovation and value for money than bespoke systems.

Road user culture and behaviour

3.10 Three kinds of technology systems affect road users: road-based systems, road users’ own systems, and third-party systems.

3.11 For road-based systems there is a long-standing distinction between mandatory "control" systems – traffic signals, dynamic speed limits, lane closures etc – where compliance is high, and "information" systems where compliance is much lower (and highly variable). This distinction appears to be becoming blurred with systems such as vehicle-activated speed limit signs, which are treated as "reminders" rather than instructions.

3.12 Driver systems have emerged in a big way over the past few years, particularly satellite navigation and route guidance systems. Simultaneously, public transport users are increasingly benefiting from travel information available from mobile phones. This kind of development gives users a more direct control over their own travel.

3.13 Unfortunately there is a conflict between individual optimisation and system-wide optimisation. For instance, if a motorway is becoming congested ahead, any individual driver might do better by diverting through side roads – but if everyone took this advice, the system as a whole would immediately choke the side roads. This is particularly likely when responding to an incident (thus prolonging or spreading its effects). There appears to be little that network managers can do to prevent this kind of behaviour, though there may be scope in reaching agreement with driver systems providers regarding permissible diversion routes.

3.14 Third-party systems are currently limited to fleet management (for freight or for public transport fleets). In future, there may be many other systems, including vehicle-to-vehicle ("V2V") communications or external bodies directly limiting vehicles’ speed ("intelligent speed adaptation", ISA). We are not aware of any behavioural research in this area – the recent European project on "cooperative vehicle infrastructure systems" did not include any [1] ; but we expect this to complicate matters further, by providing quasi-official directions which may be at odds with tactical network control. (Satnav information already does this to an extent.)

Intelligent traffic management schemes

3.15 There are many technologies that could, in principle, contribute to "intelligent traffic management", in that they capture, analyse, project and disseminate information about how road users should be directed and/or advised. Authorities are open to considering most of them, though they will quite properly look for evidence that they will make a positive contribution.

3.16 There are few comprehensive economic studies on their impact. The DfT’s most recent attempt resulted in a "toolkit" of mechanisms and likely effects, rather than a cost-benefit analysis [1] . The toolkit does, however, provide many detailed results such as:

· "The Cleopatra project in London found that 58% of respondents would immediately respond to VMS congestion warnings, of which 83% would reschedule their journey and 6% would change modes."

· "Following implementation of SCOOT [in Southampton], there were 18% and 26% reductions in journey times during the am and pm peaks respectively. Corresponding reductions in delay of 39% during the am peak and 48% in the pm peak were achieved. Economic benefit (excluding accident savings) equated to £140,000 in 1985."

· "11% saving in [Cardiff bus] journey times in peak period. Where priority given to all buses, 4% journey time saving and 45s improvement in schedule adherence. Where priority given only to late buses, 3% journey time saving and 90s improvement in schedule adherence."

3.17 The US Federal Highways Administration has recently published a 160-page report [2] which summarises the results of almost 100 separate studies. The largest single contributor of economic benefit was electronic toll collection – but this was against a baseline of cash-based toll collection. Second in importance was traveller information (conceived as variable message signs). However this report covered studies on benefits from current technology deployment: unevaluated, underused and developing technologies would not show up as important.

3.18 Localised benefits studies for specific interventions are more common. Work done under the UTMC programme found substantial quantifiable reductions in congestion arising from car park guidance systems (in 2004) [3] . Older work [4] has shown benefits of area-wide traffic control, of bus-triggered signal priority, etc. These are not always focussed on congestion benefits – some studies relate to environmental aspects such as air quality improvements [5] , or to road safety [6] .

3.19 In light of all these technical possibilities, the key challenge is to build useful products into useful, coherent, and effective schemes. This calls for some key skills, including scheme design, scheme evaluation, and project management. These skills, typically provided through a mixture of authority staff and contractors, are in short supply. It can be challenging for small authorities in particular to ensure that the right skills are available.

3.20 Partly for this reason, some schemes have emerged as collaborative among two or more authorities. But this collaboration also has a more strategic value. Where neighbouring authorities operate independently, the roads running between them may not be coherently managed and this can give rise to unnecessary congestion; collaboration avoids this.

3.21 It can be difficult to establish and operate schemes across multiple authorities, especially if the local transport policies diverge. Successful partnerships include:

· Authorities with a historical connection [7] (Kent/Medway, Hampshire/ Southampton/Portsmouth, Dorset/Poole, etc)

· Authorities in a metropolitan area, for public transport (where the Passenger Transport Executive can lead/coordinate)

3.22 Areas where collaboration is generally recognised as necessary but underprovided include:

· Links between the strategic and local roads networks [8]

· Authorities in a metropolitan area, for road network management [9]

· Sub-regional integration between "hub" and "hinterland" authorities

3.23 Anecdotal evidence suggests that much of the most serious congestion on the urban and inter-urban road network is caused by problems on the strategic network. (We are not aware of any research to quantify this.)

Legislative provisions for road management

3.24 The principles of the New Roads and Street Works Act 1991 (NRSWA) and the Traffic Management Act 2004 (TMA) are widely supported. Sharing information about roadworks provides the potential to minimise the disruptions they cause. Similarly, monitoring and managing the local road network by an authority, mindful of the impact on other parts of the network, is necessary to minimise the congestion caused by vehicular free-for-all.

3.25 The devil, however, is in the detail. In respect of TMA in particular, it is unclear what constitutes adequate management, "so far as may be reasonably practicable having regard to their other obligations, policies and objectives", to comply with the Act [1] . In practice, therefore, the effect is essentially to codify the LHA’s role in legal form.

3.26 With both NRSWA and TMA, there are systems and data issues that cause practical difficulties in network management.

· Systems to manage streetworks do not export data that can fit into systems that manage traffic. If they did, it would be possible for fixed control systems to be reconfigured, semi-automatically, around temporary traffic lights, which could alleviate significant congestion around urban streetworks.

· Systems used within different authority areas could, but generally do not, send live network data to each other. If they did, it would be possible for an area’s systems to respond to traffic which is about to enter the area, and to forewarn drivers to problems in neighbouring areas.

3.27 Like UTMC, the Electronic Transfer of Notices ("EToN") specification for streetworks is supported by DfT [2] . It has, however, been difficult to engage to resolve this issue.

Impact of bus lanes and other aspects of road layout

3.28 Broadly speaking, congestion occurs when the number of vehicles on a road section exceeds its capacity for one of two reasons:

· The incoming flow of vehicles is too high

· The speed of vehicles is too low

3.29 An example of the first might be where two lanes merge into one. One possible effect of a bus lane, if badly designed, is to create this kind of anomaly; however, paradoxically, a bus lane could relieve this congestion [1] by taking out the second lane "upstream".

3.30 An example of the second is at a junction. Vehicles slowing to turn and/or to give way can cause the junction to back up. There is a balance between no control (drivers move whenever they can), roundabout (fairly steady low speed circulation) and traffic signals (alternating between stationary and higher speed): which is best will depend on local details.

3.31 Technology systems provide an added layer of management which can, unlike road layout, respond dynamically to changes in flow patterns – for instance, morning and evening peaks will usually have different predominant directions.

3.32 Technology systems can also help to predict the effect of changing road layouts, in particular through running simulation models. However it can be very computer-intensive to achieve a reliable model in a dense urban network.

4. Recommendations for action

4.1 We believe that central Government has a role in helping local highways authorities manage their networks more efficiently, including through technological mechanisms like UTMC.

4.2 We would like to see more encouragement for, and guidance on, cross-boundary operations. This might be through:

· Open technical standards (building on initiatives like UTMC)

· Operational codes of practice (building on initiatives like the HA’s National Guidance Framework)

· Full-fledged shared services (building on ITAs and LEPs)

4.3 We would also like to see more encouragement for, and guidance on, cross-functional operations. Traffic management systems should understand and respond to (systems used for):

· Roadworks

· Incidents and accidents

· Environmental management

· Land use planning

4.4 As recent circumstances have shown, there remain challenges in the collection, collation and dissemination of appropriate information to the travelling public in the event of traffic disruption. While this is a legitimate public expectation, it is genuinely hard to get right, and can be expensive and risky. We believe that targeted research on how to fulfil citizens’ needs cost-effectively would be widely welcomed by local authorities.

4.5 We believe that the work of good local projects should be made available to others, to minimise "reinventing the wheel". This not only enables a faster rollout of good practice; it also makes for a more streamlined and more robust supply sector.

4.6 We consider that there should be stronger incentives for local highways authorities, and their communities, to create the links and good-practice libraries that this implies.

4.7 Most of the investment required to achieve this will be in local schemes, or for developments within the systems industry. However DfT has a key role in political leadership, in particular to ensure that the various initiatives are "joined up".

January 2011