I commute on a steel road bike. Sometimes I pass "roadies," sometimes they pass me. Sometimes I pass people on CitiBikes, sometimes they pass me. I just keep going at my pace. I don't see why some people need to make commuting a race. I have had some people pass me dangerously just to be in front, and others who are going slower will often pass me at a stop light, forcing me to pass them again and again. It's stupid and dangerous.