Are Variable Message Signs effective?

Rasmeet Kohli, Managing Director, Envoys Electronics Pvt Ltd, said, “In India VMS is used as a message display board to display safety messages. There are many variants in VMS depending on requirements for highway traffic and for urban traffic. VMSs have different sizes of boards; colour options (single or true colour) for text message only or with road/safety sign (pictorials) and text in combination. There are many new safety features introduced in VMS which can inform the Control Room about the health status of VMS messages being displayed, unauthorised access to open VMS door and LED/pixel failure detection.”

Challenges

It is better not to show any message at all than to show an ill-founded message. It is recommended that messages that are immediately relevant for driver behaviour and expectations should be displayed. Vehicle activated signs (VAS) can be effective for reducing speed. This is particularly true for such sections of the road that need adaptation to a considerably lower level of speed. If there are road sections where sudden locally limited impairments such as fog, slipperiness etc are common and often cause problems, these can be reduced by simple warnings that increase the readiness of the driver at the same time as the driver spontaneously reduces his speed a bit.

A forewarning should be given, if possible, about a VMS message further ahead. With a forewarning, the driver will look for the message and be prepared to read it. The message should be repeated at least once. The probability of missing the message is then minimized. Credibility demands fast and reliable updating of messages. Travelling time information is preferred by the drivers for guidance. The message should be valid “here and now”, i.e. from the signpost where it is shown to a well defined point on the road further ahead.

VMS messages should be fixed – they should not flash or run. The reasons are that flashing and running messages make reading and catching the information more difficult, as well as draw drivers´ attention away from traffic. A bank of well formulated short messages should be used. The messages in the bank should cover all realistic incidents and situations.

Complex VMS systems require firm specifications as well as continuous quality checks of every part of the system (technique as well as organization). Some examples of malfunction of complex VMS systems: The VMS is often out of order. The manoeuvring system is often not reliable. Information to the traffic control central from incidents and occurrences on the road is often insufficient for giving the road-users relevant VMS messages. Warning messages are often sent out too late and are not updated frequently enough. Any verified documentation of which VMS messages have been shown on the road is usually lacking. The VMS messages are often not harmonized or standardized. The drivers often have difficulties to understand the messages. The organization for operation of the system (traffic control, maintenance and verification) has often not had the resources for making the system work properly.

However in India, the awareness and utilisation of VMS has not reached its full potential both in urban areas and highways. Many of the urban areas do not have such signs and even if installed, hardly communicate any relevant information to motorists. On highways, either the VMS are very few in numbers and / or are located in non-incidental areas, giving no benefit to the motorist. Most of the times the VMS carry continuous social and awareness messages instead of any travel guidance or incident information. And hence, the seriousness of reading the message is lost due to the same message being replayed all the time. The probability of losing relevant message is a series of routine social messages is always high. Normally a VMS should not show any messages until a relevant message has to be conveyed to the road user. So any message flashing on the VMS conveys a sense of emergency reading for the motorist who shall than take a conscious travel decision further.

Scope of VMS in India

Europe has a very mature ITS market and VMS has an important role in the traffic management systems. The main role of the VMS is to provide variable or dynamic traffic signalling and to provide traffic and road conditions information, in real and useful time, to the road users. By doing this it is possible to improve safety (less accidents), to improve mobility (less incidents and traffic congestion) and to improve the comfort and confidence of the users of the road infrastructure.

With an important role being played on safety and mobility issues, VMS should be used or installed in critical spots on the main road infrastructures like on highways, in tunnels and on bridges. They are also installed on main access points to cities and highways. By analysing the road conditions and traffic behaviour, one can identify the spots where accidents or incidents and congestion occur. VMS & traffic management systems are installed at these spots beforehand to prevent such type of situations.

António Carneiro, Director, Masstrans Systems (P) Ltd, said, “The economic impact of these improvements due to a VMS is quite significant though these are not so visible at first glance. But when we analyse the costs related to traffic accidents, incidents and traffic congestion (energy consumption, time loss, productivity loss), we understand easily that improvements on safety and mobility have an important impact on economic development”. Microprocessador Sistemas Digitais, SA (MP), Portugal is Variable Message Sign (VMS) manufacturer and provider of safety and mobility solutions.

Despite being promoted as a means to improve the efficiency and safety of the road network, the focus of most advanced technologies thus far has been on improving mobility rather than safety. For example, variable message signs are often installed for the sole purpose of providing travel advice to drivers even though they can be used to communicate a wide variety of messages. However, once installed, it is simply a communication device and could be used for promoting road safety when not used to display traffic related information.

India has a huge potential for the ITS market in general and, for sure, it includes VMS systems. This is visible in the ongoing investments in transport infrastructure since it is a key factor for a sustainable growth of the economy. With the infrastructure there will be the need for Intelligent Transportation Systems (ITS) in order to manage, control and optimise the investment.

Preeti Swaminathan