Birmingham to Dunchurch The road starts on the
A4540 Birmingham Ring Road, bypassing
Small Heath and crossing the B4145. It passes over the
River Cole and meets the
A4040 at a
grade-separated junction at the
Swan Shopping Centre in
Yardley. It meets the B425 at traffic lights in
Sheldon, then enters the
borough of Solihull. The section of the A45 from Birmingham city centre to the M45 is all dual carriageway — urban dual carriageway with traffic lights until
Birmingham Airport, then rural grade-separated between the airport and
Coventry. The Bickenhill Junction (grade-separated) intersects with the B4438, a dual carriageway access road for the airport, the
NEC and
Birmingham International railway station. In December 2024 the new A4545 opened, replacing part of the southern section of the B4438, providing an alternative direct link to the
M42. There is another grade-separated junction with the
M42 junction 6 (three level grade separation with roundabout). On this junction, there is also access to the
National Motorcycle Museum. The road meets the
A452 at
Stonebridge at a grade separated junction and passes over the
River Blythe where the road briefly enters
Warwickshire.
Meriden is bypassed to the north. The
Heart of England Way passes under the road, and the road enters the borough of Coventry. The A45 becomes an urban road and skirts the south side of Coventry, crossing the A4114 near Allesley Park, the B4101 at Tile Hill,
West Coast Main Line,
A429 and B4113. Beyond here the road takes a more rural nature, with a grade-separated junction with the
A46 and the
A444 (three level roundabout with underpass for the A46 and the A444, and an overpass for the A45). Between here and the next junction, the A45 runs concurrent with the A46. The Tollbar End roundabout was one of the busiest in the Midlands. It had exits for the A46 north / Coventry Eastern Bypass,
Coventry Airport and B4110. In early 2017, the Tollbar End roundabout was upgraded and the junction is now a roundabout interchange with an underpass for the A46. Crossing the
River Avon, the road re-enters Warwickshire. The
A423 exits to the south-east at a (grade-separated) forked junction near the former
Peugeot factory. The
A445 crosses at a roundabout near
Ryton on Dunsmore, followed by the War Memorial Roundabout with the B4455
Fosse Way. This
Portland stone memorial
obelisk on the roundabout just north of
Stretton-on-Dunsmore commemorates
King George V's review of the
29th Division before they were sent to
Gallipoli. There is a further grade-separated junction with the A4071 and B4453 towards
Rugby. The final roundabout on this section is the start of the
M45 and the B4429. For , the A45 runs concurrent with the M45 until a fairly new junction beyond
Dunchurch. The B4429 carried the A45 until the new junction was built.
Dunchurch to Thrapston . Heading towards
Daventry, the road is
single carriageway. The road passes two prisons:
HMP Onley and
HMP Rye Hill. After
Willoughby, the road enters
Northamptonshire, where it crosses the
Oxford Canal and
Grand Union Canal near
Braunston. The
Jurassic Way crosses the road here. The road enters Daventry and briefly runs concurrent with the A425 heading to
Leamington Spa, then heads south-east on the Daventry bypass, here called the Stefen Way. The road meets the B4038 at a roundabout where the A425 exits. The road heads west past
Dodford and then bypasses
Weedon Bec, crossing the
West Coast Main Line and
Grand Union Canal and then meets the
A5 at a roundabout constructed as part of the Daventry Development Link Road realignment which opened on 15 November 2018. This road also bypasses
Flore, before meeting the grade-separated
M1 junction 16, briefly running concurrent with the M1. The A45 resumes at M1 Junction 15 as a dual carriageway, heading around the south side of Northampton. It then meets the older route (made of sections of the A5076 and A4500) at the A45 /
A508 grade-separated junction, near Northampton High School. It then crosses the
River Nene and Nene Way, and after that, there is a large grade-separated junction with the
A428 and the A5095). This section is concurrent with the
A43, which exits at a grade-separated junction near
Weston Favell. The grade-separated junction with the end of the A5076 is also the exit for
Billing Aquadrome. The road has a grade-separated junction with the B573 near
Earls Barton. The road then meets the
Wellingborough bypass (
A509) at a roundabout, although there is a segregated turn lane for westbound traffic wishing to continue on the A45. It runs concurrently with the
A509 to the grade-separated junction near the bridge over the
River Nene, where the
A509 exits south near
Irchester Country Park. East of Wellingborough, the road crosses the
Midland Main Line. There is a grade-separated junction for the A5001 into
Rushden and the route runs alongside the River Nene, offering a second turning to
Rushden at a roundabout with the A5001 again; at this second junction, the original route to the A1 has been reclassified the B645. At the roundabout with the
A6 near
Higham Ferrers, it starts the follow the former route of the
A605. The section of dual carriageway from the M1 now ends at the next roundabout and the route from there is now single carriageway. This is the start of the
Raunds bypass. The next roundabout is with the B663. The route bypasses
Ringstead and the A45 finishes at a grade-separated junction with the A14 (roundabout with overpass for the A14) near
Thrapston. ==Junction list==