This invention provides a tire for agricultural vehicles that employs a tread design having a flattened contact surface across the width and a plurality of curved lugs that alternately extend from each sidewall to a location nearly adjacent to the opposing side wall. Each lug curves so that a central section at the center of the tire width is located on the surface ahead on the circumference of adjoining sections of the lug that extend toward each of the opposing sidewalls. In this manner, each lug appears to have a curved “banana” shape that extends across the width of the tire contact surface in a generally axial alignment. The grooves between lugs extend generally axially across the width, as a result. They are narrowed, having a circumferential width that is between approximately 20% and 30% of the average circumferential width of a lug. This geometry places more lug surface in contact with the road for better handling and longer tread life and provides less groove space to retain mud and detritus. This geometry also causes more accumulated mud and detritus to be squeezed from, and ejected out of, the tire prior to the transition onto hard road from soft ground, thereby reducing undesirable tracking on the road surface.