Rude?

Out of respect for others I am always on time or a little early (5-10 minutes at the most). Maybe I am just a freak but to me being on time = respect. I find it disrespectful when people are always late. I have a friend who is always, and I mean always, late. She will call 10 minutes before she is supposed to be here and say she is just now leaving. She lives 25 minutes away. Which means she will be here in 35 minutes. At first I ignored it but it has become an ongoing problem. Today we had a certain amount of time we could spend with the kids at the zoo. Her lateness caused a ripple effect in the day. We spent less time enjoying ourselves (it takes 30 min. to get to zoo;had to leave by 1 p.m. so she could make it to pick up her hubby at 2; left 1 1/2 hours to see zoo and feed kids) and more time driving. Like I said...maybe I am a freak about this but I found it rude. I understand that it happens sometimes. Every time though?! I know some people are just late people. So in saying that wouldn't it have been responsible (knowing there is a time constraint) to show up on time? For those of you who fall into the late category I think 5-10 minutes is okay but anything more is kinda rude. The later than the 10 minute mark, I find it more disrespectful. So calling a few minutes before you are supposed to be there and saying you are just now leaving and live a bit away is quite rude and disrespectful. If you are already most of the way there and call is not as disrespectful. It at least shows you at least tried to get there on time. Like I said...maybe I'm a freak about this. Am I overreacting? I don't think I am. But if I am I'm sure one of you will let me know.