The B1517 follows the pre-bypass A153 through the centre of Sleaford.
The road starts at Quarrington roundabout where it leaves the A153 at the A15 western bypass and heads north-eastwards into the town centre. After a dog leg by way of South Gate and East Gate (a gyratory system sends north-east to south-west traffic through the town centre along Carre Street and Boston Road) the road heads out of town along East Road to terminate at Bone Mill Junction on the A17, where the A153 reappears.