In developing nations across South America and Africa, it is common for travellers on buses and trains to be offered snacks by street vendors. Fresh fruits and packaged confectionery are generally the safest option, followed by home made crisps (potato or plantain) and savoury parcels (empanadas or samosas). For those with sturdier stomachs there are 'meat' kebabs.
But in Asia, where space is at a premium, vendors set up market stalls right by the train tracks. How close? This close.