|Length:||10 mi (20 km)|
| A507 road
The A5120 is an A-class road in Bedfordshire, linking the conjoined towns of Ampthill and Flitwick to Dunstable and, via the M1 motorway, Luton and London. It connects with the M1 at junction 12, being the sole road at this junction, in close proximity to the Toddington services. On its route from Ampthill to Dunstable, the A5120 serves Westoning, Harlington, Toddington and Tebworth. Unusually for an A-road, it does not meet another A-road at any point between its start on the A507 and its end on the A5. This would change if the A505 Dunstable North Bypass were to be built, however.
When the A5120 meets the A5 in Dunstable, the latter is multiplexed with the A505 road. The road passes through the Houghton Regis area of Dunstable as it approaches the town from the north. The road actually continues past the A5, without its A5120 number, as an unclassified road, into the Beecroft industrial estate, where it meets the B489 road from Ivinghoe.