Sentence:  Long before the final design for the Borders Railway was adopted and then implemented, CBR had argued that the 35-mile route - comprising 30 miles of new line extending southwards from Newcraighall - should be designed with a <WSD>two-tier</WSD> service in mind. This would comprise stopping services running as far as Gorebridge (12 miles south of Edinburgh), and faster limited-stop services covering the whole line to Tweedbank. 
Meaning of the word marked with <WSD> tags:  Having or consisting of two tiers.