Getting a Taxi

My wife and I are staying at the Holiday Inn in Jan.
She will be attending a conference at the presidente-intercontinital a few days and I am wondering how far apart they are. She will have to be there by 7:30 am and she is worried about being able to get a taxi. Can anyone help us out?

There are always an abundance of taxis, especially at that time of the day, 7:30 am. In the lobby of the Holiday Inn there is a board that posts all of the taxi rates.