The Department for Transport places significant emphasis on Managed Motorways to achieve smoother, more efficient traffic flows and reduce overall journey times in its 2008 publication Roads – Delivering Choice and Reliability.

Currently, there is only one scheme in operation in England using the hard shoulder as a running lane when traffic volume is high – the M42, Junctions 3A to 7. However, this is not the case elsewhere in Europe, where the use of Active Traffic Management (ATM) techniques is much more extensive.  

The PIM project

The Netherlands is particularly advanced in this field, with 17 schemes to date involving hard shoulder running, which have increased capacity by between seven per cent and 22 per cent and significantly improved journey time reliability. The examples set by the Netherlands provide useful information in applying these techniques to the UK, particularly as the number of Managed Motorway schemes is expected to increase considerably over the next few years.

The Highways Agency and its Dutch counterpart, the Rijkswaterstaat, are currently engaged in a partnership programme known as the PIM project, which was officially launched at the Dutch Embassy in London in January 2006. The project provides each organisation with the opportunity to learn from the others’ experience.

To ensure successful delivery, each agency brought in a consultancy to provide expert advice and assistance. Grontmij was appointed on behalf of the Rijkswaterstaat. The Highways Agency has mainly used the project to learn about Dutch technologies and experiences used for traffic management on the strategic network, including Managed Motorways.

Learning from Holland

Safety

Hard Shoulder Running is now 10 years old in the Netherlands and operates on 300 kilometres of Dutch motorway. Many have expressed concerns about the safety of hard shoulder running in the UK, with particular worries about multiple pile-ups on the hard shoulder. Critics have suggested that the good safety record on the M42 scheme is a result of the rarity of hard shoulder running in the UK, meaning motorists pay more attention and take more care when driving on this section of the motorway network. 

However, the Dutch experience is that the safety record has not deteriorated as the amount of hard shoulder running on their motorway network has increased. This should give confidence to those promoting the expansion of hard shoulder running on the UK motorway network. 

Variable Message Signs

The National Traffic Control Centre (NTCC) is the Highways Agency’s primary centre for collecting data from the roadside, assessing the impact of events and notifying drivers via Variable Message Signing (VMS), traffic radio broadcasts and the Highways Agency’s website and telephone service. Grontmij has worked on the NTCC project over the last 10 years, overseeing the work undertaken by the NTCC operator, including the installation of a significant roadside infrastructure, such as 600 automatic number plate recognition camera sites and 2,015 loop monitoring sites.

As the NTCC interacts extensively with the Regional Control Centres (RCCs), Grontmij has been heavily involved in defining and evolving interfaces for the NTCC to communicate with the RCC technology, particularly CCTV cameras, VMS and the in-station systems. The library of real time information on the inter-relationship between congestion or incidents and delay will be valuable in informing the prioritisation of the forthcoming Managed Motorway schemes, yet there are further advances in VMS deployment in the Netherlands which the UK can benefit from.

Some of the more recent developments in VMS in the Netherlands include:

• Text signs to advise of queue length or travel time, together with a + or - to show whether the queue length is increasing or decreasing. This makes the information more useful to drivers in considering their route options.
• Deployment of two pilot graphical signs. These signs have been better understood and more regularly followed by drivers than the text signs. One such sign is currently in use on the approach to Amsterdam Ring Road – the red colour indicates sections of the ring road currently subject to congestion, enabling drivers to make an informed route choice.

Value for Money

A common feature of many of the Managed Motorway schemes will be the regular use of the hard shoulder as a running lane by traffic which contains a relatively high proportion of heavy goods vehicles. The performance of the hard shoulder pavement under heavy traffic loading is often unpredictable, as the previous negligible traffic usage may mean that the foundation has not consolidated to the same degree as the adjacent very heavily trafficked lane one. Decisions on the treatment of the road pavement in the existing hard shoulder can have a significant influence on the construction cost of each scheme.

Specialist pavement design and assessment, including Falling Weight Deflectometer (FWD) testing and analysis, combined with analytical design of inlays, can enable maximisation of the reuse of existing pavements or foundations, saving expenditure and assisting with carbon footprint reduction.

Unusually for an engineering consultant, Grontmij manufactures and operates the most widely used Light Weight Deflectometer (LWD) in the UK - the Prima 100 (image attached). This enables rapid determination of the overall stiffness of foundations constructed from unbound and modified materials, enabling pavement design optimisation and assumption checking, and therefore improved value for money.

Moving Ahead in Ireland

A good example of a recent major project involving substantial civil engineering works and extensive ITS elements is the Dublin Port Tunnel. On this project Grontmij was responsible for the design and site supervision of all surface works, including motorways, slip roads, bridges, buildings, the toll plaza and river works, as well as the 2.2 kilometre cut and cover tunnel.

Additionally, Grontmij specified and designed all aspects of ITS within the tunnel. These ITS elements are almost identical to those needed for a Managed Motorway scheme, including overhead lane control systems, speed enforcement, CCTV and a complex tunnel control system. Grontmij also managed the radio, public address and fire systems and assisted with the development of the safety case for the ITS systems, which are critical to ensuring safe operation of the tunnel.