Planning the intermediate road network

In April 2026, we submitted the initial document for the Zonal Road Plan of the Barcelona Provincial Council. We had previously worked on earlier versions of this plan, as well as on the provincial road plans for Lleida and Tarragona. Local roads, often described as secondary roads, play a key role in linking municipal streets and rural paths with county, regional and national roads. They form the intermediate layer of the road network.

Their design and management are especially complex because they include very different types of roads. Some carry very little traffic but remain essential for access to small rural municipalities, agricultural machinery or natural areas. Others serve heavy traffic in tourist areas, provide access to industrial estates, connect to ring roads and avenues, or function as urban crossings. Unlike other types of roads, local road design must also consider pedestrians, cyclists and public transport. Because of this intermediate role, these roads have major importance for territorial organisation, the quality of non-urbanised landscapes and the character of urban environments.

Cataloguing roads and redefining functions

Zonal road plans study in detail which municipal roads already perform the function of local roads and should therefore be officially classified as such. At the same time, they identify existing roads that should be declassified. In principle, municipal paths that should not have road status ought to be adapted only with drainage works to prevent deterioration. In general, they should keep permeable surfaces, stabilised soils and their original width, with passing places added where needed.

Even so, some roads do not strictly meet the conditions set by road regulations but still carry high traffic volumes or heavy vehicles and play an important role in motorised mobility. In these cases, action is needed to reduce speed, improve visibility and lower accident risk.

Spatial analysis and investment priorities

For the Barcelona Provincial Council’s Zonal Plan, we carried out a detailed analysis of all roads and paths, focusing on their geometric deficiencies. Using cartographic information on the varying width of each road, and for those that met the conditions to be classified as roads, we programmed GIS routines to identify sections with significant deficits and assess the cost of solving them.

Analysing a network of local roads and paths requires both fieldwork and the use of advanced spatial analysis systems. Traffic forecasts are more uncertain than for county or primary roads because of the greater variability of local roads. Economic evaluation indicators such as IRR and NPV can still be very useful when they are limited to direct impacts such as savings in accident costs, travel time and vehicle operating costs. Indirect and induced impacts may be greater, but it is difficult to measure them with enough certainty. In these cases, a multicriteria table can provide sufficiently robust support for decision-making.