Section 5: Overhead Signs

Introduction

High-speed, high-volume highways depend on fully effective overhead signs. Therefore, it is essential that overhead signs be properly maintained at all times.
Except for supports, overhead signs should require less maintenance than ground mounted signs. This is a result of their mounting height and the materials the overhead signs are made of. Damage by vandalism is also less. However, when damage does occur, immediate measures should be taken to repair the damage if sign effectiveness is impaired. Most damage to overhead signs is caused by thrown objects and firearms, usually resulting in minor damage.

Special Equipment

Special equipment is required for economical maintenance of overhead signs, including routine maintenance such as cleaning and patching.

Supports

All overhead sign supports should be thoroughly inspected every two years for actual or probable structural distress or failure. Possible causes of distress and failure include overload fatigue, corrosion, vandalism, and collision damage. Components to be examined include:
  • foundations.
  • anchor bolts and nuts
  • base plate assemblies
  • tower columns, web members, and connections
  • span member to tower connections
  • span member chords, web members, and connections
  • walkways and connections.

Walkway

Walkways should be inspected and maintained to ensure structural integrity.