This gate has access=yes, but graphhopper doesn't route motorcars through it (but does route pedestrians):

http://graphhopper.com/maps/?point=56.375345%2C38.474765&point=56.374805%2C38.474518&locale=en-US

Barriers with access/motor_vehicle/motorcar/bicycle/foot = yes/permissive/designated should not be counted as obstacles (e.g. ignored in routing), taking into account thar narrower access classes override wider ones (e.g. motorcar overrides motor_vehicle which overrides access).