There's a access panel on the base of the pole that has a winch and lowering controls inside. There's also a power disconnect inside to cut off power to the lights. I found a picture of the insides of one Here at a Ontario highways page.
Thanks for that Info Joe....i read they used to have to go all the Way to the Top to Maintain...back when the Highmasts used Carbon Arcs and were called moonlight towers.
I remember when these exact highmasts did NOT have fixtures on them.. It was years ago.. Driving to Shreveport. Now they have fixtures. so these highmasts are pretty new.