The variant of the Regional Road (SRT) n.429 “Val d’Elsa” between Poggibonsi and Certaldo is an important asset of the larger infrastructure project, under construction, which will connect the Highway “Siena – Florence” entrance, at Poggibonsi North, with the Motorway “Florence-Pisa-Livorno”, at Empoli.
The new road section, which crosses through the provinces of Siena and Florence and four municipalities, (Barberino Val d’Elsa, Certaldo, Poggibonsi and San Gimignano), ends on the Certaldo ringroad. Politecnica has designed the new 12.3 km long section and six bridges, three of which are on the Elsa river and three on the rivers Bacchereto, Avane and Avanella.
All the Headworks have been desingned according to the latest seismic codes. Classified as “suburban main” type C road, the new arterial road has a 10,5 m cross-section, featuring two 3,75m wide lanes (one for each direction), and two 1.5 m wide side banks.
The intervention also harmonizes some critical topics related to hydraulic issues of the valley area that is crossed by the road, as well as delicate landscape topics of the Valdelsa agricultural panorama.
The lot of SRT n. 429 built between Poggibonsi and Certaldo it also part of a broader variant program which involves the territory of the Florentine Valdelsa area, where other modernization actions are foreseen.
Among the planned actions, Politecnica is carrying out the design of local traffic flow improvement and of the the cable-stayed bridge in “La Zambra”, which represents a cross-cut between the old route and the new section of the SRT 429 on order to drain traffic, mostly industrial, in the “Le Lame” town.