We used to live on a main road, with the railway across the other side.  It was noisey constantly.  It never bothered Rico or Gia.  I think it's good to have consistant noise when a baby is around, gets them used to sleeping through it.  My sister, my goodness, HAS to have her house sooo quiet for her 3 yr old to have her afternoon nap!!!!!!  She literally tiptoes around her house.  Closes every possible door, takes the phone off the hook, won't turn the jug on, etc etc.  She's really bad.  I needed to use her fax a few weeks ago and made the mistake of turning up while 3 yr old was sleeping.  Even though the door was closed to her bedroom, and the doors to lounge/kitchen were closed, my sister said she'd have to fax this form for me, after 3 yr old wakes up!!  And she was pretty much whispering to me.  If her husband is home when daughter is sleeping, he has to go next door to my mums to use the toilet.  Yeah, I think she's a little Cookoo.

My point is, don't make it unpleasant for yourself, your Dp or anyone visiting when baby is asleep.  You still need to "live" as well, and not put everything on hold while baby is napping.

Baby will be fine. We live just over from the start of the desert road and hear trucks and trains all the time and the trains are further over from the road. I grew up living next door to the main trunk line with the trains and had no issues with sleep - so my mother tells me.