The circular (Horizontal) curve length is the centerline length of the arc from A. BC(PC) to PI, B. PI to V, C. BC(PC) to EC(PT) or D. E to delta Solution The circular (Horizontal) curve length is the centerline length of the arc from C. BC(PC) to EC(PT) The circular (Horizontal) curve length is the centerline length of the arc from beginning of curve (BC) to end of curve (EC). Point of Curvature (PC) to Point of Tangency (PT)..