Trucker's Atlas - useful?

Mollusc

Hi, I'm thinking of buying the 'Philips Navigator Trucker's Britain' road atlas to settle my nerves slightly ahead of our trip to Cornwall and Devon later this month.  I wondered if other members have used this, or similar, to help avoid unsuitable roads
and if it's worth buying?  We can't afford a Satnav - spent all our money buying the Van!  Would love to hear other Member's views.  Thanks.