It depended on where in Serbia you were. At times I certainly felt out of place, and on one occasion we were stopped by a driver who basically said turn around now and I will take you to the place we were looking for, you don't want to go any further down this road. We were stopped at the side of the road because I was basically saying the same to my OH that I didn't feel that safe. He was brought up in rougher places than me, so wasn't picking up on what I was feeling and was saying we were fine, but I wasn't convinced.
But there were many, many times when we were stopped by people to be escorted into a cafe and coffee and cakes bought for us whilst they wanted to just talk with us. People often came to our assistance and helped out, but there was also one notable occasion where someone basicllay stopped us cycling into a 'war zone'. We were litterally 1 day off cycling into it when someone stopped to ask us where we were going to (only road etc) and told us that UKIP (?) forces had been given permission to use live rounds on the road we were cycling on at a particular blockade around the Kosovo area. We knew we would have been able to get through the blockade, no-one would have hurt us, but things had been getting violent and did get violent the night before (so the day we were told) we would have been there. That changed our route completely.
Serbia was one of those countries that I found difficult and whilst never threatened, I was never at ease in it either and I can't put my finger on it. It was also a country of people who were really helpful or really unhelpful, there was nothing inbetween. It was a country that we first experieinced muslim hospitality (on many many occasions) and it was also the country that defeated us for getting into legally in that we ended up cycling down an autobahn to get to the control points which had been moved off the main road (which had been shut) and onto the brand new autobahn... we ended up cycling down another autobahn to get out of the country as well.... As for cycling it, well it was another of those in areas we didn't feel safe but most of the time the driving was fine. There was an awful lot of litter at the sides of the roads though and that is sadly one of my overriding memories - litter, dense freezing fog, and muslim hospitality.