For a tool that you would want to keep with you/in vehicle everyday, for emergencies, the non locking blade is actually a good idea legally, if it did happen to lock then you would have to have a 'good reason' for having it at the very time of being stopped/searched.
If the Officer didn't agree with your particular 'good reason' then it would be down to a court/judge to decide,...if they decide not then you would receive a fine &
criminal record at least.
![Sad :(](./images/smilies/icon_e_sad.gif)