Efficient Design with many alternatives

[bobby1994]

I want to design a choice experiment with a combination of modes.

So I have for:
area 1, four alternatives (bike, e-scooter, walking and cycling)
area 2 also four alternatives (bike, e-scooter, walking and cycling)
and a main mode, train between the areas.
and car for the whole trip.

How to make a efficient design by combining these alternatives?

For example:
alternative 1 bike+train+walking
alternative 2 e-scooter + train + cycling
alternative 3 car

And how to account for the other altnatives as well?

You have a kind of ngene syntax how to do this? I have totally no clue how to combine these alternatives.