From what we are concerned,below two main points are what you care about:

1) Selecting a suitable lamp power according to road type, pole height, pole distance between each other, required floor lux/uniformity, installation method, preferred lamp's appearance, etc.

2) Recommending a right calculation for each components required for the solar system by peak sunshine duration, back-up rainy days, average temperature, the wind speed according to the local weather situation.