makes sense, they use up the most energy. 

Man, I was hoping we'd still have a few years left of an orange I-494. But on a slightly happier note just a few weeks ago I realized that I-94 west of Alexandria is still virtually all HPS (at the few interchanges that have lighting), and I think there are still sections of I-90 that are HPS. Hopefully since these aren't really "priority" areas we still have a few years left.

if they do it smartly, you'll actually grow to like the new LED high towers. 

if they do it smartly, you'll actually grow to like the new LED high towers. 

It's not the quality of the light or how well they do (then again I have seen LED highmasts before in 3000k, they didn't look too bad except for the glare being much worse than HPS) it's just that LEDs are so boring. They are instant on, no warmup, no 120hz flicker that is visible when you drive by, stuff like that. Same reason I use a 50w MV lamp for doing my homework when I could just use an LED or CFL bulb instead.

Mn/DOT has finally approved an LED replacement for the 1000 watt HPS tower lights, the Holophane HMLED3 Since a large part of the efficiency of LEDs is the improved optics to direct light exactly where you want it, the asymmetrical pattern- putting light in a narrow rectangle to line up with the road- uses 209 watts, while the symmetrical pattern- basically throwing light equally in all directions, uses 627 watts.

There's a test installation of two towers at 212 and 494, they seem like a big improvement over the fixtures being tested at 494 and 61, which don't even equal the HPS footcandles. Mn/DOT knew this but wanted to start to test some fixtures for long term reliability anticipating modeles that would equal the footcandle requirements would be developed.

There's a project to convert all Mn/DOT District 1 (Duluth) 3 (St. Cloud), 4 (Moorhead), 7 (Mankato), and Metro Districts high mast lighting to LEDs this summer with three contracts to be let April 27. 8816-2701 covers the metro and District 3, and 8816-2704 covers District 7, 8816-2733 covers Districts 1 and 4. Work will start in June and wrap up by November.

Districts 2 and 8 have no high mast lights; no word on District 6 (Rochester)

There's a project to convert all Mn/DOT District 1 (Duluth) 3 (St. Cloud), 4 (Moorhead), 7 (Mankato), and Metro Districts high mast lighting to LEDs this summer with three contracts to be let April 27. 8816-2701 covers the metro and District 3, and 8816-2704 covers District 7, 8816-2733 covers Districts 1 and 4. Work will start in June and wrap up by November.

Districts 2 and 8 have no high mast lights; no word on District 6 (Rochester)

Wonderful. I was hoping they would be spared.

And the first mass installations of LED high mast lights are going up- the Fish Lake interchange has been converted and crews are working on US 10 / MN 610

And the first mass installations of LED high mast lights are going up- the Fish Lake interchange has been converted and crews are working on US 10 / MN 610

Interesting… I recall reading somewhere earlier this summer that US-10 between MN-610 and 35W was getting full continuous at-grade lighting. To be honest, it sort of surprised me, but it makes sense when you consider that the segment between Hanson Blvd. and MN-610 already has full lighting (installed in 2012?). Still, I would've thought that the remaining few sections of the beltway would've gotten continuous lighting before any highway outside of it (the beltway) did.