Complex sentence: After local protests, early plans were modified to put more of the route into tunnels up until a point approximately from St. Pancras, previously the CTRL was planned to run on an elevated section alongside the North London Line on approach into the line's terminus.
Split into simpler sentences: After local protests, early plans were modified to put more of the route into tunnels up until a point approximately from St. Pancras. Previously the CTRL was planned to run on an elevated section alongside the North London Line on approach into the line's terminus.