King City, Salinas, Soledad and any other city/town along US101 are primarily agricultural towns (Salinas being the biggest of the three), and generally not hotbeds of criminal activity (although Salinas at least has a crime rate above the national average). 80% of the lettuce grown in this country comes from the Salinas Valley.

There are poor areas (this is an agricultural, not a financial center), but these are not big cities, and do not have serious gang/drug/crime issues.

I would think any motel alongside US101 would be fairly safe, as these cater to travelers. I personally would have no issues staying in any of these towns (but then I'm a 6' + male).

AAA would be a good bet, and perhaps tripadvisor would also be worth a look.

Salinas being the biggest town (John Steinbeck's hometown and home of the famed Salinas Rodeo) and closest to Monterey is probably where you want to look first.