Mr Kay said the operation of a free bus service depended on the numbers of pupils who were forced to travel 2.4km or more to their nearest school, and for Montessori pupils the South End classes were the only option for them in Wairarapa.
There was also a Montessori preschool running in Masterton that today had a roll of about 40 pupils, principal Pauline Harter said, and more primary school pupils were expected to enrol in July.
The launch of the bus service was vital, she said, because there were families from Masterton who had up to four siblings attending the Carterton classes and the costs of transport could top out at about $60 a week.
"I know we have some very happy parents and we're hoping more children from the preschool will be enrolled here as well. Not enough were making that transition because of the barrier of distance and the extra cost. Now that barrier and cost are gone," she said.
Wairarapa Montessori this month celebrates 20 years in the district after the first class was established in 1995 with six preschool children in an empty classroom at the then Hiona Intermediate in Masterton as a satellite of Wai Ora Montessori in Naenae.
Wairarapa Montessori primary school classes were twice forced to shift over the past two decades before Southend School "saved" the school with the merger in 2008. The classes had previously moved to the former Cornwall Street School site when Hiona Intermediate merged with Totara Drive and Lansdowne schools in 2004.
The new Montessori bus service leaves from the Tranzit depot in Masterton each morning at 8.25am. The return service leaves from outside Southend School at 3.10pm and makes drop-off stops in reverse order.