Clapham was, or is, home to one of the UK's (London's?) largest railway junctions. I would guess that in common with another famous 'railway' town, Swindon, there exists long rows of terraced houses built to house railwaymen and their families, modest, not at all unpleasant, with back gardens, yet rather back-to-back with very limited parking spaces due to the narrow streets. (My Swindon friends, all though in decently paid middle class jobs had hardly anywhere to park, with everyone needing residents parking permits.) So, I imagine Arday's parents, being from Ghana, and children of African descent doing statistically quite well at school, likely had aspirations for the young Jason albeit the area they were in was likely rather run down and depressed in parts with affluent areas conjoining it, not dissimilar to places like Islington, in North London. Willesden Junction, another railway town, is particularly grim, full of factories and rundown council estates.