I ride on city streets. Fortunately, in San Diego most of the main streets have bike lanes which greatly enhances the feeling of safety. My 6 mile commute to work takes 25-30 minutes, depending on traffic, stoplights and the wind. I commute in shorts and a t shirt and in winter wear tights. I put my work clothes in a gym bag and tie it to my rear rack with bungee cords. I keep sport coats and a suit at work. I ride every day except when it rains (not very often in SD)
I ride over 7000 miles annually. About half of that is commuting and half is weekend rides. I ride with 2 recreational clubs and most of my weekend rides are 40-50 miles. Here in San Diego, we have lots of hills, so if you ride a lot, you can't help but to do lots of hills. My wife rides to work every day too. She and I usually take an annual bicycling vacation somewhere with a touring company such as Backroads or Cyclissmo Classico.
Recently, I took my car in for repairs and put my bike in the back to ride to work from the garage. I forgot to take my bungee cords, so tied my gym bag down with a strap that I had in my handle bar bag. Although it was only a mile to work, the strap broke and the bag fell off. Unfortunately, although I heard a bang, I thought it was a car exhaust and did not know it was my bag. It contained my wallet and checkbook. I immediately cancelled my checking account and credit cards. I left work early that day to see if any messages might be on my phone regarding my bag. Lo and behold, there was one from a fisherman who found it on the street and had it with him on his boat. I immediately drove back downtown and to the dock where his boat was. Although he had already left for the day, his crewman had the bag and returned it to me. I wfelt exceedlingly grateful and extremely fortunate. I gave him a $20 reward.