What is the allegation?
Are you confident this is the police? They wouldn't normally have interviews in service stations.
Ok. it is a matter for you ultimately.
I wouldn't agree to do a voluntary interview there.
I would approach a solicitor and get them to negotiate an appointment to attend at the police station with you. It will make a difference to whether or not legal aid is available.
Yes, you do need a solicitor. Dangerous driving is a serious offence and aggravated by a common assault although the truth is that this is probably just a driving without due care.
Can I clarify anything for you?
No, not usually. You are not in need of an appropriate adult so it is either alone or with a solicitor.