Installation

Overview

Click here to download a printable version of this page.

The Strieter-Lite is a wide-angle model, multi-purpose reflector. Properly installed, it provides complete reflective light coverage for any roadside terrain.  The (printable) complete Installation Manual explains and illustrates how to install the reflectors on two lane highways and on multi-lane dual highways.

This page provides information about these specific installation procedures for two lane highways only:

Click here to see a PDF document showing pictures of these 11 typical installations:

  1. Single mounting method using Telespar posts
  2. Single mounting method using standard "U" posts
  3. Back-to-back mounting method using Telespar posts
  4. Back-to-back mounting method using standard "U" posts
  5. Alternate back-to-back mounting method using Telespar posts
  6. Alternate back-to-back mounting method using standard "U" posts
  7. Reflector's off-set up to 40 feet from pavement edge
  8. Reflector installation for downslope areas using Telespar posts
  9. Reflector installation for downslope areas using standard "U" posts
  10. Example of vegetation control using chemical defoliation
  11. Example of reflector installation where guard rails are present

Click here for further information from a user (Dennis Randolph) about proper spacing, installing on curves, required materials,  recommended equipment, typical installation crew, end conditions (where the installation ends), and deep snow on the ground.

Reflectors directed across the road and staggered

Here is a diagram showing a typical primary layout with reflectors directing light across the road.  Note that the positions of the reflectors are staggered.

A diagram showing how installed Strieter-Lite reflectors have interlocking fields of reflection, for complete coverage of road and off-road areas.

An animated GIF showing how car headlights strike the Strieter-Lite reflector, creating unnatural and apparently moving lights which frighten wildlife away from the highway.

The installation procedure is to determine the location of the line of reflectors along each roadside, taking into consideration the amount of offset desired, width of usable shoulders, guard rails, vertical vegetation, drainage ditches and embankments. The reflector lines are not required to be equally distant from the centerline of the highway or the same distance from the highway edge. (The highway does not need to be centered between the lines of reflectors.)

The reflectors may be offset up to 40 ft from the active edge of the highway, provided the distance between the reflector lines does not exceed 125 ft. The spacing of the reflectors along the highway (longitudinally) must always be equal to the distance ("D" in the diagram) between the reflector lines (perpendicular to the highway). When the distance between the lines of reflectors is changed, the spacing must also be changed to remain equal to the distance between reflector lines. This spacing is applied to level ground, inclines and outsides of curves. Reflectors on the inside of curves should be evenly spaced and staggered from reflectors on the outside of the curves.

The reflectors are mounted on highway delineator posts with the bottom of the reflector 24 to 30 inches above the crown of the road. The reflectors are to be staggered and directed across the highway, never directly across from each other.

Calculating the Number of Reflectors Needed

Determine where the line of reflectors are to be located on each side of the road.  Note: this may vary, depending on the conditions of the roadsides, i.e. width of roadsides, obstacles present, culvert walls, guard rails, large trees, etc.
Determine the perpendicular distance D between the lines of reflectors.
     D = total width of road + total width of paved shoulders
           + total post offsets from edge of paved shoulders
Example:   For a two-lane road (12' per lane) with 10' shoulders and
posts offset by 6' from the edge of the shoulders,
     D  =  2 (12') + 2 (10') + 2 (6') = 56'


Example

D= 56'

 

The spacing down the road D must be equal to the distance between reflector lines D.

 
Divide the length of the proposed site L by the spacing D and add one reflector for the end.  Then multiply by 2 for the two sides of the road.
Example:
     L = 1/4 mile = 5280'/4 = 1320'
     NS = 2 (L/D + 1) = 2 (1320'/56' + 1) = 2 (24 + 1) = 50
Single mount

L = 1320'
NS = 50

  Double mounting on posts is required wherever the presence of guardrails or the lower elevation of the roadsides prevent the deer from viewing the reflectors on the opposite side of the road.  
Add the number of reflectors required to double mount where guardrails or down slopes are located.
Example:  500' of guardrails
     number to double mount = ND = 500'/56' + 1 = 9 + 1 = 10
     total number needed = N = NS + ND = 50 + 10 = 60
Total number needed

N = 60

How to Reduce Costs

Often the terrain will permit offsetting the reflectors beyond the shoulder of the road. As stated above, the reflectors may be offset up to 40 ft from the active edge of the highway, provided the distance between the reflector lines does not exceed 125 ft.  For example, in the first photo below the flat terrain permitted the reflectors on both sides of the road to be located along the outside edge of the ditch rather than closer to the road.

This decision resulted in a larger distance D and this reduced the number of reflectors needed, thereby reducing significantly the purchase and installation cost.

Also, placing the reflectors farther from the edge of the road means the time and cost for regular mowing and snowplowing will be the same as before the reflectors were installed.

 

Downslope areas

Here is a diagram showing how additional reflectors may be used to guarantee coverage of downslope areas.

Additional reflectors are required only in areas where roadsides slope downwards and where the grade elevation is such that the deer cannot view the reflector on the opposite side of the road. These additional reflectors are directed away from the road and mounted back-to-back with the primary reflectors on the same posts. Where spacing in the downslope areas is 100-125-130 ft, an interim post with a single reflector directed away from the road placed half-way between the primary posts is suggested.

High traffic areas

Here is a diagram showing how additional reflectors may be used to extend coverage further into off-road areas, for maximum protection in high traffic areas.

Single and back-to-back mounting methods

Alternate back-to-back mounting method

Median barriers

Maintenance checklist on existing installations

Proper maintenance of any system is absolutely necessary to achieve maximum results.

It is important to conduct maintenance checks at least twice a year.

  1. Replace any damaged or missing reflectors.
  2. Straighten and adjust bent or twisted posts so the reflectors are vertical and the bases of the reflector housings are parallel with the direction of traffic.
  3. Wash with detergent and rinse with clear water.
  4. Keep vegetation from interfering with the light directed to and from reflectors at all times.