Complex sentence: The sixteen BM71 trains run on the Gardermobanen high-speed railway line; normally every ten minutes, with every other service continuing westwards to Asker, serving eight stops, with plans to extend to Drammen in 2009.
Split into simpler sentences: The sixteen BM71 trains run on the Gardermobanen high-speed railway line, normally every ten minutes, with every other service continuing westwards to Asker. These serve eight stops, with plans to extend to Drammen in 2009.