§ 31-5-305 — Special speed limit at bridges and other elevated structures

(a) No person shall drive a vehicle over any bridge or
other elevated structure constituting a part of a highway at a
speed which is greater than the maximum speed which can be
maintained with safety to the bridge or structure when the
structure is signposted as provided in this section.
(b) The superintendent and local authorities on highways
under their respective jurisdictions may conduct an
investigation of any bridge or other elevated structure
constituting a part of a highway, and if he or they find that
the structure cannot with safety to itself withstand vehicles
traveling at the speed otherwise permissible under this act, the
superintendent or local authorities shall determine and declare
the maximum speed of vehicles which the structure can safely
withstand and shall cause or permit suitable signs stating the
maximum speed to be erected and maintained before each end of
the structure.
(c) Upon the trial of any person charged with a violation
of this section, proof of the determination of the maximum speed
by the superintendent and the existence of the signs constitutes
conclusive evidence of the maximum speed which can be maintained
with safety to the bridge or structure.