In the past 20 years, the Portuguese road network has been under considerable development, not only in terms of coverage of the country, improving accessibilities, but also in terms of infrastructure quality in an endeavour to meet road users expectations. These expectations include higher speed, comfort and safety on the road.uThis development is presently based on the National Road Plan drawn up in 2000, which structured the national road network, to a total of about 11,500 km, and defining a B minimum level of service (as established in the Highway Capacity Manual) for main routes, involving about 3 000 km, and a C minimum level of service for the remaining extension of the network. In order to guarantee the desired levels of service and adequate road safety, projects must comply with the Portuguese Road Administration (IEP) standards, which cover the geometry of the layout, traffic signing and road safety, as well as the other components of the project. A nationwide project has recently been launched (SEQUER - Road Safety, Quality and Efficiency - 2000 to 2006). It is managed by IEP and involves a number of initiatives, such as defining the criteria for assessing the performance of infrastructures, setting up a safety auditing system and conducting in-depth investigations of accidents in the road network and any corrective measures that need to be taken. More than 30 public and private bodies are involved in the project, all linked to the planning, construction or operation of the network. The estimated funding is about EUR 9 million. Road users give high priority to the quality of road pavements, which affects the riding quality. The performance indicators that are used to describe it are defined in the road administrations' standards (IEP or motorway concessionaires). They vary, depending on whether the pavements are newly built or already in use and, in the latter case, they are related to the maintenance management systems adopted for each type of network. The performance indicators usually considered are surface distress, longitudinal and transverse unevenness, adhesion indicators (friction and texture depth) and bearing capacity (deflection). Pavement maintenance in the national network not under concession is currently performed through maintenance contracts. In the network under concession, routine maintenance is performed directly by the concessionaires whereas periodic maintenance, and especially rehabilitation works, are carried out by contractors. The maintenance techniques currently used are described in the report. The increased use of in situ recycling using emulsion and/or cement and in plant recycling are also mentioned. The use of foam bitumen, asphalt rubber and high-modulus bituminous mixtures is also becoming more common. Porous asphalt is usually used for wearing courses in areas with higher rainfall, while ultra-thin friction asphalt concrete layers are used in other areas. Maintenance works usually lead to traffic constrains. Traffic is diverted onto part of the carriageway and, eventually, on the hard shoulder previously strengthened, or diverted onto temporary diversions built off the carriageway. On motorways, the traffic is transferred to the carriageway not undergoing maintenance, at least during the construction of the wearing course. In urban areas and heavily trafficked roads (typically carrying more than 30,000 vehicles a day), the work is done at night time (10 p.m. to 6 a.m.). For the covering abstract see ITRD E135448.
Samenvatting