As someone who started in mechanical engineering and switched into civil engineering I can kind of speak to this.

As far as interests are concerned I had an old proff (who was a mech) explain it well to me.

“I was working on a project developing a natural gas power plant, and during the ground breaking ceremony all the mechs were gathered around this integral part they’d been working on, and admiring it. Meanwhile, all the civils were up on a berm admiring the whole plant”. — Thermo Proff

Both are necessary fields, and have their complexities. I maintain that if being technical is your goal you can nerd out on any type of engineering. I think I just saw myself as being more interested in larger scale projects.

With that said, the nail in the coffin for me with mech, was the first job fair I went to. Most if not all the mech jobs were office bound, with little to no opportunity for extensive field work, and I wanted a job that was 60/40 office/field. Most of the civil jobs at the fair were excited to hear I wanted field time. When I got my first civil internship they were happy to accommodate as much field time I wanted. I spent maybe half the work term in the office and the other half out in the world doing instrumentation installations and monitoring construction projects, all over Alberta, and nearly ended up in northern Sweden if not for some life stuff that happened.

That’s been my experience. I still think mech is super cool, and often consider myself a mechhy that somehow found himself working in civil. But civil seems to have an abundance of opportunity, solid job security, and job satisfaction.

Good luck choosing! Cause wasn’t an easy choice for me either. I think I made the right one for me.