Hong Kong has conducted its first test involving Shenzhen authorities of clearance procedures and private car access at the revamped Huanggang border crossing, ahead of a massive exercise next week involving 20,000 people to fully assess the facility’s capacity.No 2 official Eric Chan Kwok-ki said Saturday’s drill went smoothly and passenger flows were orderly, with speedy pickup by public transport, although a motorist association reported traffic jams along the San Tin Interchange roundabout...