COLUMBIA, Md. (AP) — Tract housing, white picket fences and two-car garages may not define the suburbs for too much longer.

In suburban Maryland town centers, such as Columbia, Towson and R0ckville, developers are showing a distinct preference for mixed-use projects that provide residents easy access to nearby retail and office spaces. The changes in design are being driven by millennials who prefer a more urban lifestyle and baby boomers who view these kinds of developments as cheaper and easier to age in.