Drivers can expect disruption and delays from Monday as Brighton and Hove City Council starts a transport survey.
The council warned that any motorist may be asked to pull over and answer a few questions but added that delays would be kept to a minimum.
The survey starts on Monday 11 October and will be carried out at various points across Brighton and Hove on various dates with the help of Sussex Police.
The council said that it wanted to “build a picture of transport use in the city”.
The survey will also involve counting pedestrians, cyclists, vehicles and train and bus passengers.
There will be household surveys and some face-to-face interviews with drivers at the side of the road.
The council said: “The survey will only take around a couple of minutes.
“The information the council receives will provide accurate and current information which can be put into a computer-based ‘transport model’ which will allow the council to test and plan for the future.
“These traffic surveys may cause some disruption but the council and police will monitor traffic flow to ensure that drivers are not delayed for too long.
“At busy times drivers will be handed pre-paid postcard survey forms.
“People are encouraged to participate fully in the surveys as this will make sure the information the council collects is as thorough as possible.
“We will be grateful for the patience of anyone who passes through a survey point.”