避免 concentrate more on the abstract sense of to avoid so you usually hear 避免问题 避免矛盾 避免事故（的再次发生）it goes with issues 避开 is more for to avoid substantial object or actions like 避开那辆汽车 避开别人的目光/注视 躲避 is to try to avoid sth. while the first 2 is to avoid and （suggestively）to have avoided it already；and 躲避 is more for objective meanings

It's not easy to explain.In many case,these wards have the same meaning and the same use.But in some particular situation you have to use the right one.and that require time and experience.(frankly many native ones cannot use it correctly).I suggeste that you should look up a chinese-english dictionary.at least,there are the most accurate,professional definition.

避免：设法不使某种情形发生；防止预防。 1.避免冲突 2.看问题要客观、全面，避免主观、片面。 避开：.躲开,不接触。 1、他有意避开她。 躲避：故意离开或隐蔽起来，使人看不见。 1、这几天他好像有意躲避我。 避免一般是对事情，避开和躲避一般指对人。 避开和躲避类似，可互换。避开更有计划性，提前量更长一些。

下面是一些例句。 避免： 我们一定要提高警惕，避免再犯同样的错误。 to prevent sth from happenning 避开： 一辆跑车飞驰而来，行人们吓得赶紧避开。 她转身凝视着那条河，避开他的目光。 躲避： 为了躲避追兵，这支部队已经走了三天三夜了。 避开 is the same as 躲开，but sounds more formal. But 避开 and 躲避 are not the same. The character "开" implies that the action/process of hiding has ended. 躲避 only means you are hiding from sth.