The A17 is a major route for large goods vehicles (LGV) accessing Lincolnshire and Norfolk from northern England and the Midlands and is also a major holiday route particularly in the summer months for cars and caravans making their way from the north of England to East Anglian seaside resorts of Hunstanton, Wells-next-the-Sea, Sheringham, Cromer and Great Yarmouth as it is one of only two direct routes which link Norfolk with the A1, the other being the A47.

The western end begins in Winthorpe, Nottinghamshire, on the eastern side of the Newark bypass, where it meets the A46 at a roundabout, with access to the A1.

This section passes over the former RAF Winthorpe (now Newark Air Museum, and there is a roundabout for Newlink Business Park.

It crosses the River Witham as part of the dual-carriageway Beckingham Bypass which was built in 1972 at a cost of £600,000, where there is a left turn for Carlton-le-Moorland.

[citation needed] It passes across Leadenham Low Fields, with the Lincoln Cliff seen in the distance.

Leadenham is built on the side of the Lincoln Cliff, which the road no longer passes through, which gives access to the A607.

In March 1995, the £3.3 million bypass was opened and the route passes through Leadenham Park to the south of the village.

The Leadenham Bypass had been planned for over thirty years, and had started out as a dual carriageway which would have been the safest option (but more expensive) for the amount of traffic that the road carries.

It meets the former route (with access for Pottergate Road to Wellingore, and the A607) and passes across Fulbeck Heath.

At Cranwell and Byard's Leap, it re-enters North Kesteven at the line of the north–south Ermine Street (now the Viking Way).

The road used to briefly follow Ermine Street southwards to Byard's Leap with its cafe,[2] and then eastwards to the current route at the B1429 junction.

The former route has a 13 ft 9in low (railway) Boston Road Bridge, another important reason for building the bypass.

In March 1991 the ship was holed and sank when, on a falling tide, she settled on a dislodged limestone boulder used to reinforce the Welland channel and was cut up on site later the same year.

The bypass, New Washway Road from Saracen's Head to Laurel Lodge Farm, opened in 1989.

[22] This bridge retains its swing function necessary for access to Wisbech port for pleasure craft and small coasters.

Just east of the bridge the turning to the left provides access to the "Sir Peter Scott Walk" coastal path and "Snowgoose Trust" bird sanctuary.

In Terrington St Clement, there is a crossroads at Balsam Field, for Tilney High End to the right, at which there is the African Violet Centre with a cafe.

From this point all the way to the A47 junction, the road is the parish boundary between Clenchwarton to the north, and Tilney All Saints to the south.

The improved follows the former Spalding to South Lynn, part of the Midland and Great Northern Joint Railway (M&GN), which closed on 2 March 1959.