The fifth Bandai Thomas Town series was released in April 2001 and included the first road character, Bertie, and the first narrow gauge engine in the series, Rusty. An archived copy of an old Japanese fansite that shows the series with its track can be found here.
Bertie originally came with a station with a mechanism that lets him roll out as if departing. His front wheel rollers are smaller than the rear.
Donald includes a turnaround section with a tree that can be turned to make a horse run around. I am pretty sure the main reason the licensing stickers for this series are white instead of black is so they stand out on the twins.
Douglas includes a turnaround and a junction with a set of signals.
Rusty includes a railroad crossing which fits nicely with Bertie in the set.
Thomas included a straight section with a pedestrian overbridge and another railroad crossing with operating gates. Like the rest of the series, the Thomas in this set has a white licensing sticker.