В файле GamePC.cpr есть параметры, отвечающие за трафик, его количество и поведение. Как редактировать, смотрите в теме про Bugatti SS.

AI]

// VehicleMaxCount is the hard limit of simultaneous AI vehicles
// But you can set TrafficMaxCount+ParkedMaxCount > VehicleMaxCount
// Example: vehicle=16 traffic=16 parked=8
// -> you can spawn up to 16 traffic if no parked vehicles on the area,
// but only spawn up to 8 traffic if 8 parked are here
// and 0 parked cars if 16 traffic cars are already spawned
//
VehicleMaxCount = 16
TrafficMaxCount = 8
ParkedMaxCount = 4

// Maximum count of Traffic AI that will be physics enabled at the same time
PhysicsMaxCount

// 1st radius: Traffic cars inside this radius will switch to physics (for a max. of PhysicsMaxCount cars)
// 2nd radius: Removable cars outside this radius will be uninstaciated
// fov dist.: Visibility coef is ponderated by [1..0] when dist to camera is [0..fov_dist]
// fov magnitude: not used, apart for debug tests
//
// 1st radius 2nd radius fov dist. fov magnitude
CullingConfig 100 500 1000 45

// Ratio Visible MinTimeInterval MaxTimeInterval
SpawnConfig 0.6 0.2 0.4

// Traffic cars will appear all around the player car, on a circle which radius will be:
// radius = speed * reaction_time
// radius clamped such as: min_spawn_dist < radius < max_spawn_dist
//
// Reaction Time Min Spawn Dist Max Spawn Dist
SpawnDistances 4 200 400

// If you want to see only a certain list of traffic car models, uncomment and modify this:
// (you can have several ForceCarModel at the same time)
//ForceCarModel "SUV2" // this is the file name, without the extension
//ForceCarModel "COMPACT1"
//ForceCarModel "BUS1"