Juvenile court hearings shall be held at a special session of the court for that purpose and each case shall be heard separately, except that two or more cases may be heard together in the following instances:

1. (1) Cases involving violations of motor vehicle laws or ordinances where none of the cases involves death or serious injury to persons.
2. (2) Cases arising in whole or in part out of a single transaction or series of related transactions.

[1993 c.33 §201]