Grids are better than culdesac but worse than randomness for a human brain so that it would be interesting to walk there. Wide roads aren't good for walkability in any sense: even if we ignore huge noise and pollution created by lots of cars, wide roads are more dangerous to cross and since it's wide you as a pedestrian need to walk more on non pedestrian infra to get to points of interest. Walkability isn't just about being able to walk