On designated shopping streets, the first floors should have glass with shops or businesses visible. This makes for safe streets and active one's. One long blank first floor on a street can ruin the feeling of an area.
Lights and wide sidewalks of brick and trees creating shade and buffer for childs safety can all be done by the city.
In Portland, new buildings in the Bayside neighborhood have and have not been placed tight to the sidewalks. The DSS building sets back behind a parking lot in a suburban layout, destroying any hope for Marginal way to feel like a room there. The new university housing however, forms a wonderful outdoor street space and has a nice bus stop of glass in front. This simple rule can have dramatic positive results.
Streets are public space and have much potential for safety, and the pursuit of happiness!