Gardening at the roadside

I have been thinking about ways to make my (hopeful) future space as productive as possible. While I like ornamentals, I am most motivated by growing things I can eat (with attracting pollinators and growing green compost also important). So, until I have more space for fruit and veg than I can handle, I want to pack as much as I can into every available bit of garden. 

I am going to have a reasonable size south facing back garden (hard to be sure on Google maps, but I think around 112 square metres, or 1200 square feet for the old'uns), though some if that will end up being paths, shed, pond, compost bins etc. However, there's also a smaller north facing front garden. The top bit will be very shaded by the house for most of the day, but the bottom two thirds look like they may get a bit of sun as there isn't really shade from the east or west. In an ideal world, I'd like to get some fruit and veg growing there as well, but I would want to grow things that will be okay next to a main road. I'm thinking leafy things and herbs will be difficult to wash, but perhaps there are other options that would work well? 

Until I live there, I'm not going to know for sure how busy the road is, but I don't think it is going to be too bad. Although it's a main road, it's on a spoke that just leads up to the top of the (populous) village (where there are a couple of schools and a GP surgery) then out into countryside. I don't think there will be heavy traffic. So, hopefully it will be okay to grow some food there? 

I'm looking for ideas of things that will be easy to wash, won't look a mess growing in the front garden, can cope on a slope, and don't need too much full sun. What do you think?