Farmers have started to harvest their crops this fall and the Highway Patrol is urging you to be cautious on the roadways.  Heavier farm machinery is going to be on the roadways and possibly moving slower than the rest of traffic.  Most drivers will have slow moving vehicle emblems and tend to stay close to the edge of the road to allow traffic to flow around them but at times can be impassible.  Trooper with Troop E Clark Parrott tells KZIM-KSIM to be patient with farmers. Last year there were a total of 231 traffic crashes involving farm equipment.  3 drivers were killed and 17 injured.  Of those incidents 10 farm tractor passengers were injured as well.