Emergency services were called to two separate incidents on the A41 bypass this morning (July 15).
Officers were first called at 6.45am after a vehicle which had overturned on the northbound carriageway towards Berkhamsted ended up on the grass verge.
The two people inside the car had freed themselves before emergency services arrived but a Herts Police spokesman said they did not require any treatment.
Officers were then called again to the second incident at 7.50am, this time on the southbound carriageway towards Tring.
A Herts Police spokesman said it was a two-vehicle collision recorded as damage only.
The occupants of both cars were able to move off the carriageway and exchange details.
The incident was dealt with by 8.30am.
Elsewhere, there was congestion on Breakspear Way in Hemel Hempstead due to a plank of wood blocking the carriageway near Junction 7 of the M1.
This was cleared by 8.20am but tailbacks continued from the town.
Traffic is now flowing freely.