Why practitioners match by modalities
Motion sickness is one of the clearest situations where modalities decide the remedy. Two people with 'travel sickness' can need completely different remedies based on what makes their symptoms better or worse and what else they feel.
The four remedies most often discussed
Cocculus indicus
The classic travel-sickness remedy. Nausea and vertigo are worse from watching movement and better from sitting still with the eyes closed. Often paired with exhaustion from broken sleep.
Tabacum
Tabacum pictures include pale, cold, clammy, sweaty people who feel dreadful from any motion — including the gentle rocking of a boat. Often the person wants fresh cool air on the face.
Petroleum
Petroleum is considered when excess saliva and nausea are prominent, especially if fumes (petrol, diesel) make it worse. It is one of the remedies people mention when their worst travel is inside a car rather than on a boat.
Borax
Borax has a particular association with downward motion — aeroplane descent, lifts, being lowered in a car park ramp. Some children specifically dread these moments.