Sudanese entrepreneur Mohamed Samir watches proudly as workers assemble garishly coloured rickshaws, unique in the North African nation because they run on electricity in a bid to tackle soaring costs. In Sudan, three-wheeler vehicles — tuk-tuk rickshaws for passengers, and motorbike tricycles with a trailer attached for carrying goods — have long been a popular and affordable transport. Tens of thousands ply the streets of the capital Khartoum alone. But with Sudan gripped by a dire economic crisis made worse by political unrest following a military coup last October, the cost of running pe…