El declive del proyecto hemisférico y de la fragmentación regional

In recent years, one of the factors that has influenced pavement maintenance management in general is environmental sustainability. For this reason, several practices in recent years have raised the need for sustainable pavement maintenance. The National Cooperative Highway Research Program (2011) conducted research into the matter and discovered the following issues and considerations in relation to pavement maintenance:

• Identifying ways to implement and use environmentally sustainable practices or operations and treatment

• Applying life cycle assessment (LCA) and cost analysis methods in pavement preservation and maintenance

• Conducting research to collate information about environmentally sustainable practices in pavement maintenance management to guide practices, as well as training to improve the skills and competencies of personnel

• Conducting research to determine the viability of recycled or alternative materials for maintenance and preservation of pavement

• Conducting research to determine and establish standards (i.e. noise standards) in pavement preservation and maintenance throughout the life cycle

• Conducting research to quantify the frequency and extent of damages on pavements such as the number of cracks to accurately measure the time needed for repairs or maintenance and resources or materials

• Conducting research to influence policy development in pavement maintenance, identify new technologies to use in pavement maintenance and repairs, and establish new specifications, materials, equipment, and standards in relation to environmental sustainability

(National Cooperative Highway Research Program, 2011)

In carrying out pavement maintenance, engineers and managers need to take into consideration various issues when deciding on options and methods of working. Such issues include dealing with existing Statutory Undertakers’ buried services, the need for traffic management and traffic diversion, dealing with listed structures etc. The following sections present a review of some of these issues (Ziad, 2009).

2.4.3.1 Statutory Undertakers’ Apparatus

Roads do not only carry vehicular and pedestrian traffic, but also there are usually several Statutory Undertakers’ pipes and mains buried beneath the road base (Ziad, 2009).

A major issue when carrying out any pavement maintenance therefore is dealing with existing buried services during construction. An initial search and consultation is undertaken with the main Statutory Undertakers to ascertain the presence and location of any of their buried plant or equipment within the sections to be maintained. The following organisations are usually consulted (Ziad, 2009 cited HAUC, 1992):

• British Telecommunications plc;

• National Grid (Transco) for gas mains;

• The local water company (United Utilities Water Services in the North West of England);

• The local electricity distribution company (United Utilities Electricity Services in the North West of England); and

• Other telecommunication and cable companies known in the area such as NTL (Virgin Media).

Following the initial consultation, a detailed search is required to verify the accuracy of the details, check on any other services present and measure the actual positions and depths of each service before a detailed design of road works commences. The extent of any service alterations is dependent on the nature and scope of the proposed road works (Ziad, 2009 cited HAUC, 1992).

Any necessary service diversions or alterations are carried out by the relevant Statutory Undertakers or their agents, and the diversion can sometimes be completed prior to the main road works contract or programmed as part of the main construction duration to minimise traffic and other disruptions in the area (Ziad, 2009 cited HAUC, 1992). The approved document that governs the required actions where major road works or major transport works affect Statutory Undertakers’ apparatus, is the Code of Practice:

Works), published by the Highway Authorities & Utilities Committee (HAUC), under the auspices of the New Roads and Street Works Act 1991 (Ziad, 2009 cited HAUC, 1992).

The cost of diverting Statutory Undertakers’ plant is a major issue, as under the New Roads and Street Work Act 1991 (NRASWA) cost-sharing principles, the highway authority must carry 82% of the total cost of the diversion while the Statutory Undertaker bears 18% of such costs (Ziad, 2009 cited HAUC, 1992).

The cost of service diversion or alteration can be extremely high, and the ultimate design will carefully consider the need for actual diversion, and whether it would be feasible and acceptable by the relevant Statutory Undertaker to support services under consideration in place and protect them for the duration of the road work instead of the more costly diversion option (Ziad, 2009).

2.4.3.2 Traffic Management

Carrying out pavement maintenance work can potentially cause a severe hindrance to existing traffic as well as to the normal life of the local community. Where the work is likely to involve full or partial road closures to facilitate the safe completion of the road works, this will cause disruption and possible traffic congestion affecting local residents, traders, through traffic, pedestrians and cyclists. This can be extremely costly in terms of lost time to motorists, noise and dust on diversion routes as well as safety and environmental considerations (Ziad, 2009).

The impact of road works on traffic is therefore a major concern and needs careful planning and close coordination with many agencies, such as the Police and emergency services. The local authority coordinates all work carried out on the road, and notifies all agencies and organisations concerned of any planned work on the road or such involving traffic management and diversion in particular, well in advance (Ziad, 2009).

Traffic management issues, the need for traffic diversion and the availability of suitable diversion routes are most important considerations in the selection of options and methods of undertaking road works (Ziad, 2009).

2.4.3.3 Dealing with Listed Structures

Buildings and structures are listed in order to protect the best of the country’s built heritage. Currently the listing in England and Wales comes under the Planning (Listed Buildings and Conservation Areas) Act 1990 which puts a statutory duty on the Secretary of State to compile a list of buildings of special architectural or historic interest (Ziad, 2009 cited Craven District Council, 2007).

Buildings and structures that are listed are subject to a much greater degree of control in respect of alteration and demolition than other structures. A building that has been listed will not be demolished, extended or altered if there is no permission from the local planning authority, because even what may appear as minor alterations to a listed building or structure could alter its character and as such, a ‘Listed Building Consent’ would be required (Ziad, 2009 cited Craven District Council, 2007).

For pavement maintenance schemes involving listed structures, it is therefore vital to start early consultation with the local planning authority to determine the need for a Listed Building Consent, and if required, comply with any conditions imposed by such consent to allow the proposed road works to proceed in a timely manner.