In this article I’ll talk about ASP.NET MVC Routes and Regular Expression. I based my article from the Fredrik Kalseth’s Blog about Defining Routes using Regular Expressions in ASP.NET MVC. Fredrik provides a Custom Implementation of Route in order to be able to use Regular Expression Patterns with MVC Routing. However we are not able to use that with the MapRoute Extension Method of RouteCollection. So Here is a Custom Implementation of the MapRoute Extension Method which takes advantage of RegexRoute Implementation made by Fredrik.