The 40-metre-long (130 ft) and 3.2-metre-wide (10 ft) bridge features three segmental arches with a span to rise ratio of up to c. 3:1.^[1] Its spans are 2.80 m, 7.90 m and 11.40;^[2] the thickness of the two larger arch ribs is between one and two Roman feet,^[3] making the structure one of the few Roman bridges whose ratio for rib thickness to span is lower than the commonly applied ancient standard of 1:20.^[3]

The bridge was built of local limestone whose shape varies according to its function: the arches consist of voussoirs, the spandrel walls of irregular stonework.^[4] The main pier is protected both upstream and downstream by large triangular cutwaters out of rectangular blocks of stone.^[4] The paved roadway rises sharply from the left bank to the main arch, and then drops in a gentler gradient to the higher bank on the other side.^[4] The parapet, which has been reported as partly removed by O’Connor in 1993, has been apparently repaired in the meantime.^[2]

According to the Italian bridge builder Gazzola, the Pont sur la Laye dates from the end of the 1st or beginning of the 2nd century AD,^[4] thus belonging to a round dozen known Roman segmental arch bridges.^[1] Structurae, though, ascribes an early Romanesque origin to the structure (11th century).^[2] Following the Mane homepage, the two side arches, along with their breakwaters, were added as late as the 17th century,^[5] which means that the segmental arches are of a relatively late date.

• List of Roman bridges
• Roman architecture
• Roman engineering
• Romanesque architecture
• List of medieval bridges in France

• O’Connor, Colin (1993), Roman Bridges, Cambridge University Press, pp. 96 (G4), 169, 171, ISBN 0-521-39326-4

  Media related to Pont sur la Laye at Wikimedia Commons

• Pont sur la Laye at Structurae
• Traianus – Technical investigation of Roman public works