Lucknow, Nov. 11 -- A private bus which overturned at the zero point of the Lucknow-Agra Expressway on Monday, killing three people and injuring around 45, had five unpaid challans worth Rs.27,000, regional transport officer (enforcement) Prabhat Pandey said. Its papers, including its fitness and permit documents, were valid, he said. The bus was carrying around 56 passengers despite having a seating capacity of 40. Pandey said pending challans do not prevent a commercial vehicle from obtaining or renewing its fitness certificate, permit or tax clearance. "If a commercial vehicle has a challan, its other work does not stop," he said. A pending challan can affect the issuance of a no-objection certificate and the transfer of a vehicle, he added, but other transport-related services remain available. In practice, this means an operator may leave fines unpaid and still renew documents required to keep a bus on the road. Pandey said linking pending challans to more services could make enforcement stricter. The cause of the accident is still being investigated, while officials are also examining whether the bus's left tyre burst, Pandey said. T After the crash, deputy chief minister Brajesh Pathak wrote to the additional chief secretary (Home), the transport commissioner, the Uttar Pradesh Expressways Industrial Development Authority (UPEIDA) chief executive officer and the managing director of the Uttar Pradesh State Road Transport Corporation. He directed officials to arrange driver health and sobriety checks before vehicles enter expressways....