I know a fella who is bike commuting to Philadelphia from the outlying suburbs. The round trip runs around 60 miles. So this is a substantial commute. On the advice of his trusty friend, the Internet, he decided to invest in some high powered lights. The lights require that the cyclist attach the battery packs to the bike frame.
So armed with a huge backpack and his huge body (he is 6'6") and the fabulously powered lights, he said biking became a whole new adventure. On his way in, during daylight, he turned the lights on as he approached the city limits. He said all of a sudden, he noticed that cars and buses started giving him a wide berth. Coming home it had become dark and he had both the front and back lights blaring, he said the wide berth experience was even more pronounced. Buses hung back and passed him slowly as the drivers gave him the OK sign. On four lane roads, cars moved over to the passing lane.
People stared at him. He passed a high school soccer game and he said they all turned to look. So the investment in the high powered lights was worth every penny. No one buzzed him. No one gave him the finger and swore. Apparently the motorists had no idea who or want he was. Being a large male certainly helps but he has been hassled and buzzed on his bike. The big difference seems to be the lights. They create an impression that he is either a police officer or someone important. No matter what, the lights seem to keep him safe.
Here is the link to the company he used to buy lights: DiNotte Lighting. My son bought a tail light with 240 lumens. So spend some serious cash. It's cheaper than an ER visit.
If you are a commuter and plan on doing it regularly, go get some good bike lights. I want them now. Although an old lady on a bike with high powered lights might not elicit the same response as a huge 20 something male on a bike.