'multi-lane' originates from English as a compound: the combining form 'multi-' comes from Latin 'multus' where 'multi-' meant 'many', and 'lane' comes from Old English 'lanu' (via Middle English 'lane') meaning 'path'.

'multi-' entered English as a combining form from Latin 'multus' in later periods of English, while 'lane' developed from Old English 'lanu' into Middle English 'lane' and then modern English 'lane'; the compound 'multi-lane' arose in modern English to describe roads with many lanes.

Initially, 'lane' meant a general 'path' and 'multi-' simply meant 'many'; over time 'lane' narrowed to a traffic-specific sense ('a marked division for vehicles'), so 'multi-lane' now specifically means 'having multiple marked traffic lanes'.