What is the Vision?

The main objective of providing Safety-Related & Real-Time Traffic Information to the road user is improving the safety and the efficiency of the network. This includes both pre- and on-trip, and gives them a better driving experience (i.e. they can plan with confidence, adapt trips, stress is reduced, lost time reduced).

Expected and unexpected events can develop into a traffic bottleneck, due to abrupt reactions of uninformed drivers. However, if those drivers know the upcoming traffic situation in advance they would be prepared and could pro-actively adapt their speed and following distance, thus preserving smooth, stable and safe traffic flow.

Real-Time Traffic Information Services allow traffic information to be factored into both pre- and on-trip journey planning. This can alter the departure times, assist the driver to take more effective routing decisions, select another means of transport or even alter the decision to travel.

The provision of information to drivers enhances the travelling experience even if the information does not directly impact on network efficiency or safety. Better-informed drivers tend to be calmer and hence more concentrated. Other impacts are the increased mode share of public transport and reduced air pollution.

What are the Missions?

The main service mission is to inform about expected or unexpected events in order to support the road user finding the best way to travel and to do so in a calmer and safer way and provide accurate and timely information on traffic conditions and travel times to support travellers in making appropriate, safe, trip choices.

This predictive or real-time information could be provided on-trip and pre-trip using different information channels, accessible or receivable by the road user via different end-user devices. The service may comprise common information as well as individual (personalised, on-demand) information.

Problems to consider:

• different organisational and technical conditions among traffic managers, road operators for the dissemination of information
  • take into account the individual backgrounds and requirements of each partner
  • promote dialogue between traffic operators along corridors for homogenous way of dissemination of information
• diverging interpretation of the infrastructure by the road users
  • communication to the road user as far as possible through clear and mono-interpretable pictorial signs. Use of language only as explanation for the signs used
• diversity of information portable with different presentation including on board system
  • promote use of common criteria for presenting information (i.e.: common color for level of service)
• Difficulty for the road user in easily accessing information (in relation with the European Commission requirement for a universal minimal set of information)
• Incompleteness of information
• Timeliness of information
• Uncertainty of any prediction
• Inconsistency in the presentation of information to the road user, across different information channels and portals (diverging interpretation of the information by the road user). To offer high-quality individual (personalised, on-demand) information, the co-operation with public bodies and private commercial partners/service providers is crucial.
• Inconsistency of the information provided in accordance with any traffic management plans (TMP, see TMS-DG07) which are in operation of the road authorities or traffic management centres
• With respect to an actual change of travel behaviour and a alternative choice of traffic mode or travel route, the pre-trip travel planning via navigation systems or route planners must be completed by a forecast of traffic conditions that it may not be possible to deduce just from historical data. Here the municipalities and the regions can give essential information about planned traffic-related construction or even significant events. This locally available expertise is necessary because no traffic relevance can be derived from the mere fact that an event takes place. Experience of the visitor behaviour and corresponding traffic streams should be considered.

What is the contribution of SRTI & RTTI to overarching European ITS-objectives

The deployment of Traveller Information Services in the second EasyWay period (2010 – 2012) should contribute towards the overarching objectives for 2020. The work already undertaken by the Evaluation Expert Group (EEG) during EW I will help illustrate the benefits of traveller information service implementations in terms of the above objectives and underline their contribution to EasyWay objectives. It is acknowledged that ITS evaluation is complex; the achievement of these targets could be affected by other external factors outside the control of the EasyWay project. Currently there is no (agreed) methodology on how to measure the contribution of a single TIS service to the overalls goals set; so input from the EW EEG should be sought.

Overall, the initial EasyWay evaluation shows that where services have been deployed, the benefits delivered are in line with the objectives set by the project. The deployment of on-trip Traveller Information Services and warning within EasyWay (e.g. roadside and on-board information) have shown a positive impact on road safety (up to 11% reduction in injury accidents during adverse weather conditions), mobility (up to 20% reduction in travel times with roadside VMS) and environment (up to a 10% reduction in energy consumption, with commensurate impacts on CO2 emission). When displayed pre-trip (e.g. internet, travel time predictions), the impact of Traveller Information Services on safety and congestion is lower (up to 2% reduction in congestion) but the provision of co-modal information, which aims to foster modal shift, could lead to a greater reduction in CO2 emissions overall.

Safety

SRTI & RTTI has three Primary impacts in increasing road safety.

The first is largely theoretical. It assumes that an increase in mode share for public transport can be achieved through high quality pre-trip and co-modal traveller information. The reduction in traffic levels on the road in turn has a positive impact on safety by reducing the number of accidents and managing demand on the road asset particularly at peak times. It is also generally accepted that travelling by public transport is inherently safer than travelling by car, the UITP states that the public are 10 times more likely to be involved in an accident travelling by car that by public transport .

A more direct impact of traveller information, although still difficult to quantify, assumes the timely provision of on-trip traveller information reduces accident rates. For example, informing drivers of extreme weather conditions or current traffic conditions ahead of their travel can increase drivers’ awareness and therefore reduce accident rates. For example, in San Antonio Texas, deployment of dynamic message signs combined with an incident management program, resulted in a 2.8 % decrease in crashes.

Information which principally addresses the efficiency of driving such as travel time information also has an indirect safety effect as informed travel leads to less risky driving behaviour. Past TIS studies have revealed that traveller’s value timely information on the traffic conditions, and that real-time traffic information reduces travel uncertainty and the stress due to uncertainties .

Network Efficiency

In a similar manner to safety, supporting increased modal shift toward public transport requires good quality pre-trip and co-modal traveller information. This allows for more efficient pre-trip routing decisions and/or departure times; thus increasing network efficiency and improving asset efficiency. On-trip information related to current road conditions (i.e. travel time, weather status/ warnings) should have a positive impact on network efficiency as drivers should use this information to make more effective travel decisions. In future it may be possible for well informed travellers who improve their choice of mode, route and departure time to contribute to a more even spread of traffic throughout the day. Relevant research in this area has shown that:

• making information services work well under incident conditions is likely to be cost effective
• providing travellers with information as early as possible is likely to increase its effectiveness in terms of behavioural adaptation.

Environmental Impact

The positive environmental impact of SRTI & RTTI is primarily tied to the increase in network efficiency noted above. So, for example, avoiding stationary or slow moving traffic will reduce congestion and therefore emissions of CO2 and other air pollutants. More recent research also indicates that where such information is available the more environmentally conscious traveller may, by comparing the impact of their vehicle journey with public transport alternatives, opt for the most environmentally friendly journey choice. Furthermore, keeping the environmentally aware driver informed “on trip” of environmentally sensitive areas and linking this with suggested speed control may promote better compliance with the variable speed limit. In France, it is common to reduce the general speed limit by 20 or 30 km/h on a temporary basis, generally in case of high temperatures, with the aim to reduce air pollution and smog.

Traveller Information Services Radar Diagrams

The radar diagrams below, Figure 6, show the strength of the relationships between the TIS Services and the EW objectives. The applied scales for the service radars are based on an expert view and not on specific scientific analysis.

As shown in the radar diagrams, the main benefits delivered by SRTI & RTTI services relate to safety and efficiency; the main objectives of the majority of road operators, the EasyWay Project and the European Commission. Thus, by providing road users with high quality, accessible traveller information benefits can be gained on existing networks without deploying significant additional infrastructure