Type III Long, the optics for wider coverage
In LED lighting, we do not use the reflector to change the directions of light as conventional HPS HIDs do, actually, reflectors will absorb some light.
We change the light direction with the refringence of the light, rather than reflected by some objects, the light go through it and changes direction.
IESNA has a guideline for light distributions, type I, II,III,IV,V, for road lighting, type II or type III are recommended.
To cover a 4-lane driveway, type III Long is best, however, not every luminaire is able to provide.
ARRLUX is one of the few makers that have type III long. The SLA, SLB,SLC, SI, SK models all provide this type of optics now.
More information is available upon request, IES files downloadable from www.arrlux.com