[Darteaus94025]

Yes. Bigger pipes, using an existing right of way, BUT the pipeline in the trench must be taken out of service during the upgrade, no?

[shove_it]

Maybe so, but if the pipeline companies are doing it, it must be profitable to do so.

[Tenacious 1]

Yes. Bigger pipes, using an existing right of way, BUT the pipeline in the trench must be taken out of service during the upgrade, no?

Not necessarily. You install the larger pipe next to the existing pipe and, if the existing pipe is in good repair, leave it and use it for overflow capacity or a maintenance bypass for the future. I think a lot of these "lines" are more than one anyway. Concept is the same.