Section 21-806 - Special speed limitations for elevated structures(a) On request of any local authority, the State Highway Administration shall investigate and, on its own initiative, it may investigate any bridge or other elevated structure that is a part of a highway.(b) If it determines that the structure cannot safely withstand the weight of vehicles traveling at the maximum speed limit otherwise permitted by this subtitle, the State Highway Administration shall:(1) Establish the maximum speed limit that the structure can safely withstand; and(2) At each approach to the structure, place or permit the placement of a suitable sign stating the maximum speed limit.(c) A maximum speed limit established under this section is effective when posted on appropriate signs giving notice of the limit.