What are the implications of these choices?
A longer measure brings in more revenue, obviously, and more revenue provides for a more robust investment program including more money -- for example -- for bike and pedestrian improvements, a zero- and near-zero emission goods movement system (clean trucks), and a "Grand Boulevards" program to revitalize LA County's many important arterial streets with improved bus service (perhaps an upgrade to bus rapid transit), better bus stops and real time info about arrivals and departures, bike lanes and sidewalk repairs, shade trees, signal synchronization, etc.
More money and more projects in more subregions is likely to equal more voter support. But . . . do voters get sticker shock?