Complex sentence: The buses can also be traced back to a local minibus system (黑牌車) used in the New Territories prior to 1960s and allowed to operated in urban areas of Hong Kong after 1967 to ease commuter chaos.
Split into simpler sentences: The buses can also be traced back to a local minibus system (黑牌車) used in the New Territories prior to 1960s. They were allowed to operate in the urban areas of Hong Kong after 1967 to ease commuter chaos.