Google has just added the ability to see traffic estimates by day and time for not just highways but also for many roads.

Google announced this on the Google Maps blog saying:

Here is a picture of a high traffic road in my area at certain times of the day and week:

The Google Maps team said on their Google+ page:

You can now get typical traffic for major roads as well as highways. This allows you to see what traffic will be like on different times and days of the week so you can properly plan ahead.

Pretty useful and glad this is back.

Google just also brought back live traffic data to Google Maps.

Forum discussion at Google+.