You stand still for up to five seconds, even though there are no vehicles nearby, until clearance is given. Gaps between vehicles are ignored, even though 10 vehicles could fit between them.
Ideas
Two races completed in My Team season 2 on xbox. Pit crew at level 3.
Australia. Did not effect teammate who pitted in traffic (both on track and in pit lane). I pitted from first, no cars near me. Was affected with assists. Turned off assist and loaded save from right before entering pits and was not affected. AI 75
Japan. Teammate pitted from traffic with jo other cars in pit lane was unaffected I pitted with traffic in pitlane and on track. Was unaffected. AI 70