ROAD SAFETY IMPROVEMENT AT THE MALTZAGA INTERCHANGE

Area of activity
TRANSPORT INFRASTRUCTURES

Service
Roads and highways

Client
BIDEGI – Gipuzkoan Agency of Infrastructures

Scope

• Site supervision

Duration
2017-2018

The main objective of the contract was to manage the works related to the improvement of road safety on the AP-1 and AP-8 junction in Maltzaga. The purpose of the works was to widen the roadway to two lanes both at the access junction from the AP-8 to the AP-1 in the Vitoria-Gasteiz direction, and at the connection from the AP-1 to the AP-8 in the Behobia direction. A section through which 34,800 vehicles circulate daily in both directions. The scope of the work is located in the vicinity of the Maltzaga junction between the AP-8 highway and the AP-1 highway, with a development of approximately 1.07 km of action.

The work can be spatially differentiated into two large parts associated with each of the traffic directions of the AP-8 freeway:

• Behobia – Gasteiz_Bilbao direction section, associated with the RIO SIDE of the highway, which runs from Pk 69 of the AP-8 to the abutment of the viaduct of the AP-1 branch heading towards Gasteiz. Approximate length 665 m.
• Bilbao – Behobia section, associated to the MOUNTAIN SIDE of the freeway, which covers from the exit of the tunnel of the AP-1 connection branch to Pk 69 of the AP-8. Approximate length 690 m.

More specifically, the works carried out highlight the following aspects as the main ones:

• Widening of the roadway in the Behobia – Gasteiz_Bilbao direction through the execution of different structural solutions so as not to affect the adjacent cycle path or the banks of the Deba river.
• Widening of the roadway in the Bilbao – Behobia direction through the construction of a lateral wall supported on cyclopean concrete, cemented at the same level as the base of the cunetón and the crowning being flush with the road surface.
• Stabilization of the highway cut on the southern slope (Bilbao – Behobia) through the implementation of punctual support based on GEWI type bolts, the implementation of protection mesh with a support capacity > 27 KN/M2 (surface area of approximately 5000 m2) and the placement of a dynamic barrier at the crest with a minimum protection capacity of 250 KJ (approximately 200 linear meters). Includes clearing and felling of tall trees.

Finally, work has been carried out on the installation of new road surface on the highway roadway for the extensions, both of a flexible and rigid nature. Both the horizontal and vertical signage corresponding to the new route has also been installed, including a 36 m long signaling gantry made of a three-dimensional galvanized steel structure.