More on KentOnline
The A20 was closed in both directions for nearly three hours following a crash involving a car and a motorbike.
London Road was shut close to where it passes over the A228 due to the collision, which happened between Castle Way and Town Hill.
Police, paramedics and firefighters were all called to the scene and an air ambulance was also scrambled.
It happened at 5.20pm and injuries have been reported.
Police confirmed one of the people involved had suffered "serious injuries" and are appealing for witnesses.
A spokesman earlier said: "Officers are in attendance along with South East Coast Ambulance Service and Kent Fire and Rescue.
"The air ambulance is also in attendance and injuries have been reported.
"The road is expected to remain closed for some time and motorists are advised to avoid the area while the incident is dealt with."
Paramedics treated the motorcyclist at the scene before taking them to Kings College Hospital in a serious condition.
They were joined by members of the air ambulance team, who assisted with treatment en route to London.
Some witnesses reported the traffic lights were out at the time of the crash, although this has not been independently confirmed.
The road eventually reopened at around 10.35pm.