movement from one position to another within the same social level, as changing jobs without altering occupational status, or moving between social groups having the same social status.
2.
cultural diffusion within the same social level, as the spread of fashion within one economic class.
And yet that thing is impossible to ignore, suggesting as it does a futuristic city with vertical as well as horizontal mobility.
British Dictionary definitions for horizontal mobility
horizontal mobility
noun
1.
(sociol) the movement of groups or individuals to positions that differ from those previously held but do not involve any change in class, status, or power Compare vertical mobilitySee also upward mobility, downward mobility