A strategic approach to speed management is required to develop network-wide or citywide safe streets solutions. There are a number of infrastructure and non-infrastructure methods to manage speed reduction.
Speed humps, roundabouts, and similar traffic-slowing devices can be useful to reduce speed in the immediate locations in which they are installed, however, they do not have a benefit more broadly as they tend to push traffic into neighbouring streets.
The introduction of a 40 km/h area is a more equitable and cost-effective solution that allows safe options for all people to enjoy their streets and can avoid the need for excessive traffic management devices.
In areas with speed humps and traffic calming already, these will be retained unless there is a significant change in driver behaviour.