
There are not many roads that cross into Dubai from Sharjah so the few that do tend to bottleneck quite a bit. Sharjah was popular with expats for the cheaper rent and relatively short commute into Dubai, especially when rents were skyrocketing in Dubai a few years ago (they are starting to again). I recall a sea of shared taxis charging 5 dhs to go from the center of Sharjah to various points in Dubai.