airport

automated

automatic

begin

belt

center

chain

clonk

clunk

commence

conveyor

creak

department

downwards

halt

hand

machinery

mall

metallic

mechanical

metal

motorized

mover

moving

noise

passenger

people

pound

punch

rail

rhythmic

ride

riding

screech

shopping

squeak

squeal

staircase

stairway

start

station

step

stomp

stop

store

subway

thump

train

underground

upwards

automate

motorize

move