The traffic jam bar is automatically shown in the portrait WAZE map view mode but it can't be automatically shown in the landscape WAZE map mode. Actually, this bug is already exist in the previous WAZE GPS app versions & had ever reported to the WAZE support team.

You can witness this bug when in navigation mode & the WAZE map is rotated from portrait view mode to landscape view mode & vice versa.

Perhaps a countdown timer, say to be placed either beside the speedometer or beside the orange reporting traffic/hazard type button, showing the elapsing estimated time in traffic would be practical & it should fit all types of smartphone models.