From Grantham, which was the A52's original eastern end, the road continues as "Bridge End Road" passing the "White Lion", then "Somerby Hill" eastwards, passing the "Shell Somerby Hill Service Station" on the left, rising up the valley of the River Witham to reach the ancient Ermine Street Roman road at the B6403/B1176 roundabout, which it follows for about . Ermine Street continues as the B6403 northwards at Cold Harbour. Traffic for Skegness may want to take the A153 instead (via the Sleaford bypass), as from Boston - Wainfleet, the traffic slows down. It follows "High Dike", and there is a left turn for Welby and a right turn for Ropsley.