Adjective
unroadworthy (comparative more unroadworthy, superlative most unroadworthy)
describing a vehicle which is not safe for use on the road.
All four tyres on the Commodore were also found to be unroadworthy. Source: Internet
“The aim of this multi-disciplinary roadblock operation is to reduce unroadworthy heavy vehicles on the roads by targeting driver compliance. Source: Internet