9w isn't weak for an LED. Depends on the color (each is different) but we are running 6w reds and they are far brighter than the old incandescent. Yellows run 12-15w depending on the brand. When we first switched over, we got complaints that they were too bright.
This works because LEDs are better than 10 time as efficient at converting electricity into light. On top of that the old colored lenses ate up more light as the light and that is less of an issue with LED.
The LED are not designed for servicing any more than an incandescent bulb is designed to be serviced, so not surprising you can't remove the lens.
If the old lights weren't visible what wattage were they using in the incandescent bulbs? While not as bright as LED, they were always visible. Standard we used was 150w bulbs before the conversion.
Another issue for retrofits, is does the conflict monitor recognize them turning on and off? We initially had some issues where the older monitors didn't see enough amperage to recognize which lights were on, so it would throw it into emergency flash mode.
Really not a safety thing. More of a maintenance and power consumption savings.
- Typical total wattage for a signal might average around 3600w before and not runs 350-500w. If you have a few hundred signals running 24/7, that's a sizable cost.
- Incandescent signals got replaced annually, because if a light went out (particularly a red), it would throw the signal in emergency flash. That's basically half a day for the electrician with a bucket truck playing in traffic. The LEDs we bought were warranted for 5yrs and the initial installations are going on 12yrs. If they don't fail in the first couple days, they just keep on running. After some research, we are going with 10yr replacement as LEDs don't burn out, they gradually lose light output, but still that's a lot of bucket truck time saved.