Decision-Making Software Development for Damaged Signal/Light Poles and Sign Structures
OMT (Office of Materials and Technology) metals technicians and OOTS (Office of Traffic and Safety) signal technicians of the Maryland State Highway Administration are frequently requested to investigate the damage to signal/light poles and sign structures resulting from traffic accidents. Often the circular steel tube uprights of the poles/structures have been dented. This permanent deformation varies in size and generally does not visually affect the upright. When there is no tearing of the metal at the deformation it is difficult to determine if the structural integrity of the upright has been compromised. That evaluation is compounded by the type of loading on the structure and its relationship to the deformation.
A User friendly software program is developed that can be used to evaluate the structural integrity of these uprights in the field. The program has the ability to evaluate all the types of structures presently installed on Maryland highways. The benefits of such a program relates directly to the safety of the motoring public. Information relative to the damage and type of structures can be obtained by the investigating technician and entered into the program. An immediate decision can then be made as to the integrity of the structure and the possible need to close the affected traffic lanes until the structure is removed.
The program applies the AASHTO design requirements for these types of structures and other structural analysis processes in the decision making process. The program is able to operate on the standard laptop computer in order to be effective.
Summary of Features
The objective of this study is to develop a software program that can be used to evaluate the structural integrity of the damaged signal/light poles and sign structures. The benefits of such a program relates directly to the safety of the motoring public. An immediate decision can be made as to the integrity of the structure and the possible need to close the affected traffic lanes until the structure is removed. There are seven types of poles accepted by the program:
(1) Mast Arm Pole;
(2) Strain Pole;
(3) Light Pole;
(4) Square Light Pole;
(5) Pedestal Pole;
(6) Cantilever Sign Pole;
(7) Overhead Light Pole Combined Stress Ratios(CSR) due to load combinations of
i] Dead Load only,
ii] (Dead Load + Wind Load)/1.33,
iii] (Dead Load + 0.5 Wind Load + Ice Load)/1.33,
are calculated by the program and shown on the result screen. Current Condition is calculated based on the normal design load specified by the AASHTO and Maximum Condition is calculated based on the maximum design load assumed by the Maryland State Highway Administration. Decision based on the evaluation is shown in the comment block. Output of this page is saved under the name of the pole number.