Gateway treatments signal to drivers that they are entering a Local Street, from a higher speed or higher volume street or road. They are critical for signaling to drivers that they are entering a street dedicated to safety and placemaking, where motor vehicles are guests subservient to all other users, and walkers and bicyclists may be present at any time and any place. Drivers often continue their prior speed and behavior onto local streets where it is not appropriate, but gateway treatments strongly discourage such behavior.

Full gateway treatments include raised textured pavements, raised crosswalks, and curb extensions, In combination they slow motor vehicle traffic.
If only some of the treatments are present, signing may also be appropriate. If the Local Street is designed for 15 mph, and/or shared space, the European woonerf sign, or slow streets signs from cities in the US may be appropriate.

Cobblestones on Front Street in Old Sacramento Waterfront demonstrate the effective traffic calming benefit of rough streets at gateways, and they are often used in other cities for the purpose.

The following photo shows a gateway treatment on Court Street in Cincinnati. The bollard is temporary for a special event, but the street is normally open to slow moving motor vehicles.

Just yesterday, I noted a texture treatment used for crosswalks in the downtown area of Petaluma, California. Though these are not wide enough or rough enough to significantly slow drivers, they do serve well to visually mark crosswalks as being slower areas.

Note: The term gateway is also used to refer to the entry point of a redeveloped or new commercial and housing area that the city or developer wishes to highlight. There may be decorative elements signifying the special area.
References
- NACTO Urban Street Design Guide: Gateways; https://nacto.org/publication/urban-street-design-guide/street-design-elements/curb-extensions/gateway/
- Strong SacTown Street Design Standards, Local Street Typology; https://www.strongsactown.org/2024/07/23/local-street-typology/
- Getting Around Sacramento, make streets rough again!; https://gettingaroundsac.blog/2024/06/29/make-streets-rough-again/