noun
cross-platform interchange; cross-platform transfer
Railway term for changing trains on the same platform, typically by walking across to the opposite side.
この駅では対面乗り換えができるので、階段を使わずに済みます。
At this station you can make a cross-platform transfer, so you don't need to use the stairs.
General term for any transfer or change of trains, buses, etc. 対面乗り換え specifically refers to a cross-platform transfer where you simply walk across the platform.
Compound of 対面 (たいめん, 'facing each other') and 乗り換え (のりかえ, 'transfer'), literally 'face-to-face transfer'.