The toggle for Wi-Fi only mode is found in the setting of the smart-phones’ screen. A blue bar appears at the top of the screen to inform users that the app is in Wi-Fi only mode when user switches the toggle on.       

Moreover, Google has also added notifications for mass transit delays which appeals to users who travel in bus or train. The same will inform users of disruption alerts in selected service via notifications, provided the same is available in your region.