It may just be that you need a quieter location to record. And the good NR options are not going to turn out a great recording when you aren’t putting quality in at the beginning–in other words, it doesn’t justify time and money when you are just recording with a phone.
Traffic can be very tough, as it’s often not consistent which is where NR shines. You may need to scrub out each car using spectral views or something like that.
Whatever you do, it will be a challenge.