[CMOTD]

All valid points above.

One other thing to take into account if you are starting from scratch - cost. A moderate sized two lane plastic track will require at least 50 pieces of track at an average of £5 per piece plus the cost of a baseboard. Total cost over £250. You can save money by buying second hand but you will have to wade through a lot of warped/rusty track to get enough pieces to use.

Provided you don't need magnatraction a routed version of the same layout would require a couple of pieces of 12mm mdf at less than £20 each plus a couple of rolls of decent quality copper tape at about £8 per roll. A cheap router can be found for less than £50 or you can hire/borrow one. Overall less than half the cost of a plastic track layout. This does rise if you use magnetic braid instead of copper tape though.