How do I sync travel time from iCal to calendar on an iOS device?

Hi, I really like the feature travel time in iCal. Unfortunale it only works great on the Mac. Therefor I only get the correct time when to leave when I am at home.

I have an example:

I made an apointment that is 2 hours and 3 minutes travel time away on my iMac. This is actually transferred to my iPhone correctly.

I also added an apointment with a lication in the same city. On the iMac it shows me that I will need 8 minutes from the first meeting to the second apointment and that it will remind me in time to leave. Everything seems fine. But when I look in calendar on my iPhone it will remind me 1 hour and 8 minutes before the meeting starts. That does not make any sense.

I thought that maybe iOS calendar adds the usual time set to remind me and adds the driving time. This is not the case since the usuall time is set to two hours. On the iMac the usuall time to remember me is set to one hour. It is probbably coming from here that it adds the hour but it does not make sense.

Does anynbody know how to use the travel time funktion properly for all devices?

I am also lokking for a way to set the reminder to travel time plus X minutes. It would make sence to get reminded when to get ready and not when you sit at your desk and are actually supposed to get out of the house...