Cars speeding down our street despite 20mph signs

Cars speed down our street from both ends, often getting to an estimated twice the speed limit of 20mph. There are lots of children that play in the street and I’m very concerned for their safety. Many of these vehicles are 4x4’s and can’t see children. I would very much like to see measures such as speed humps in the street (as there are on armley town street), or other measures that would make traffic have to slow down in the street.