Along similar thoughts as sidewalks, all roads of moderate traffic should have divider lines.
Locally, we have roads like the Fairview Street/Massachusetts Avenue route between Mary St and King Mill Pike and the Norfolk Avenue/New Hampshire Avenue route between different parts of the same areas. These roads that are considered two-lane, but have no middle lines despite carrying moderate traffic. Without a middle line, vehicles in each lane tend to drive way into the other lane and passing at posted speeds is risky; vehicles are forced to slow to a crawl in order to avoid an accident.
This situation is heightened by cars parked along both sides of the roads. While the road should be wide enough to accommodate the four vehicles, a lack of marked lanes leaves traffic unsafe unless extreme care is taken by the drivers. Simply marking both parking and driving lanes should resolve the problem. But, if studies determine the road needs to be widened, then it needs to be widened. This road, unlike the ones I referenced in a previous post, has sidewalks. And even though such is not necessary, these sidewalks have sizable buffers between themselves and the road, buffers that could be reclaimed for use in widening the road. Residents would probably have no problem with this use, as it would create larger and safer parking lanes. But if road traffic exceeds original designs and needs to be widened at the expense of purchasing frontage from the residents, that is what must be done.
Widening some roads and increasing their safe traffic loads should reduce traffic on other roads; for instance, widening Fairview may reduce traffic on Norfolk so that simple marking will be sufficient. While Norfolk does not seem intended to carry much load, the path it follows between Mary St and King Mill Pike make it an ideal route from the heavily-traveled Virginia Avenue on the Tennessee side to get to the shopping and restaurant areas at Exit 5 and 7 on I-81.
I'm afraid many of our local elected officials may not go in these areas often. I drive a church van route, and this route covers these areas. In some cases, modest improvements may significantly increase safety.