Baby Jogger are pros at creating easy to travel with pushchairs and the city tour even comes complete with it's own carry bag so you don't need to worry about purchasing one separately. Baby Jogger also make a range of transport bags for their pushchair range to ensure that your baby's ride is totally protected when travelling.
If it's a universal travel bag that you're after, to use on more than one pushchair or stroller, then you could try the Universal stroller travel bag from Mothercare or for a bigger pushchair, phil & teds make a great universal travel bag that you can even transport your car seat in too.
If you're wondering if there is a travel bag to suit your pushchair, then the chances are your pushchair brand will make one that specifically fits your pushchair model. It's worth checking their website to find out.
Have you ever travelled with a pushchair? Did it get damaged in transit?