Most of those are down to the inability to establish precise location through triangulation of mobile signals, SB. If you have a clear GPS signal location accuracy is much improved and if you type the location into Google Maps it will direct you to the correct location.
Your issue is down to mytaxi, Ken. If you use the Google Maps application it will show the various alternative routes with distance and ETA for each. From there you need to pick the one that suits you best. However, if you're driving a mytaxi client you're probably best advised to follow the directions mytaxi select for you.