my speedo stop working on my st200?

i was driving on the motorway doing 70 mph when my speedo just stop working after about a mile my traction control light on the dash come on and stayed on till the end of my journey but when i turned the engine off and turn it on again the the light went out but the speedo remained broken ?the car is a mondeo st200 2.5 v6 on a 2000 plate.