I will be visiting Merida again next week with my husband and two small boys as part of our yucatan visit.
(its carnival!)

We rent a car when we travel, but would feel safe taking a taxi, and we have walked about on the streets of Merida at night, day, in crowded markets, etc. and never felt uncomfortable or unsafe.

<Normal city security measures apply, for example I wear a small security pouch inside clothes with photocopy of passport, my creditcards, and cash for safety, as there are pickpocketers in any city and country, and a loss can cause delays if you are traveling and this happens!>

I think you have little to worry about in terms of drug/gang violence in Merida unless you are a member of one of those groups or engaging in illegal activity. (my opiniion) There is also a large and active expatriate community in Merida, and reading various forums and blogs, I get the general impression that even those who live there year round feel they have a good quality of life. http://www.yucatanliving.com/editori...in-yucatan.htm

saludos,
CTviajera