7.9.2 Illumination

There are two types of roadway lighting: continuous lighting and safety lighting.
Safety lighting is typically needed at interchanges, decision points, high-volume rural or suburban intersections, weigh stations, rest areas, and for safety/security for pedestrians, bicyclists and transit users.
Continuous lighting provides uniform lighting on all mainlanes, ramp terminals, direct connectors and interchanges. Continuous lighting requires the financial participation of the city. Either type may use conventional roadway lighting or high mast poles.
An FAA form 7460-1 must be completed according to 14 CFR §77.9 when lighting exceeds the following conditions for public use airports, military airport, airport operated by a Federal agency or DOD, and airport or heliport with at least one FAA-approved instrument approach procedure. If lighting does not exceed the following conditions, then the form does not need to be filed. Required notification applies to any construction, alteration, or installation of illumination support:
  • Exceeding 200 feet above ground level (AGL);
  • Within 20,000 feet of any airport type listed above which exceeds 100:1 surface from any point on the runway of each airport, with its longest runaway is more than 3,200 feet;
  • Within 10,000 feet of any airport type listed above which exceeds 50:1 surface from any point on the runway of each airport, with its longest runway no more than 3,200 feet; and
  • Within 5,000 feet of any heliport listed above which exceeds a 25:1 surface.
Considerations in the design of illumination include:
  • Coordinate illumination plans with roadway, drainage, traffic and utility plans;
  • Coordinate with LG for maintenance of proposed continuous lighting;
  • Design high mast foundations according to bore logs and HMIF standards;
  • Determine illuminance design values according to roadway classification and AASHTO’s Roadway Lighting Design Guide;
  • Execute the appropriate continuous or safety lighting agreement with the LG when lighting is to be installed within a LG's jurisdiction;
  • For lighting on bridges, coordinate illumination design with bridge details so conduit and bridge lighting brackets are included in the bridge plans; this will avoid unsightly conduit additions to bridges;
  • Meet Texas statute Health and Safety Code Chapter 425 by using cutoff luminaires to minimize glare and light pollution when installing lighting using state funds;
  • Prepare lighting justification report;
  • Use breakaway devices according to TxDOT’s
    Highway Illumination Manual
    and AASHTO requirements;
  • When designing lighting for a walkway/bikeway adjacent to a roadway, the roadway must be lit to the same level as the walkway; and
  • When possible, place lighting outside clear zone. If lighting must be in the clear zone, use breakaway poles or place poles behind or on a traffic barrier.