I feel like rubber tired automated vehicles could work with passing loops. The frequency is a bit limited due to the loop distance, but for a suburban people mover it could have good frequencies, being automated would provide superior reliability and precision, using the existing infrastructure.

Fun fact: o termo "guna" vem de miúdos do Porto que se penduravam no exterior dos elétricos para fugir aos "picas" (cobradores), que se chamava antigamente "andar à guna". Hoje quase ninguém anda à guna nos elétricos (até porque eles basicamente já não existem no Porto 😭) mas a expressão mantém-se.

Most unbearable part of threads