The Wu administration plans a 9.4-mile expansion of bike lanes in parts of the city, with advocates hoping Dorchester and Mattapan get slotted for later extensions.

The mayor and city transportation officials were in Roxbury on Tuesday to announce expansions in Allston Brighton, Back Bay and downtown, Fenway/Kenmore Square, South End and Bay Village, Mission Hill, Jamaica Plain, and Roslindale.

They added that they would be launching a citywide design process to encourage safer streets in all neighborhoods. The measures include expanding the Bluebikes program with 100 new stations, as well as adding speed humps in 30 neighborhood zones and 75 raised crosswalks at parks, libraries, and schools.

“We’re working to transform our streets so all road users are protected and everyone can benefit from the opportunities across our city,” Wu said in a statement. “Building out a safe, connected cycling network will help close transportation gaps across our neighborhoods and advance our efforts to make Boston a city for everyone.”

The city currently has 59 miles of off-street paths, and 17.5 miles of bike lanes.

Shavel’le Olivier, executive director of the Mattapan Food and Fitness Coalition, hopes the initial expansions will lead to others.

“These plans will not only benefit those who bike but also those who walk,” Olivier said. “As an organization whose vision it is to see the Mattapan community safe, clean, walkable and bike-able, we hope to see in the future biking and walking transportation expansion plans in Mattapan, Hyde Park, Dorchester, and Roxbury."

Asked about Dorchester and Mattapan getting left of the initial expansion list, a Wu administration spokesperson said Tuesday's announcement had two parts. "First is a short-term expansion of the bike network, focused on closing known gaps in places that already have significant bike infrastructure," the spokesperson said. "The second is the start of a planning process to work in our neighborhoods and with community members to plan and design the next round of bike infrastructure. Dorchester, Mattapan, and other neighborhoods will be part of that process and the outcome will shape what we build in the years to come."

This story was updated with a comment from a City Hal spokesperson.