Car & Motorcycle
Downtown, metered streetside parking is made easier by numerous vending machines that sell timed tickets that are not site specific. They are plentiful, if not cheap (upwards of $25 a day).
Outside downtown, parking is usually free but can be in short supply. In fact for many Houstonians, the availability of parking is the most important consideration in picking a restaurant. Don't be put off by valet parking at restaurants and malls; if it costs at all, it's cheap, and it can be easier than finding a space.
Houston's public transportation is run by Metro. Bus transit is geared toward weekday, downtown commuters. The exception are the fast and frequent trams ('Metrorail') which run on three routes, including the very useful Red Line that serves Reliant Park, the Rice University area, Hermann Park and the Museum District, Midtown and downtown.
Free Greenlink shuttle buses run on two routes serving major sights around downtown. Buses arrive every seven to 10 minutes.
Taxis include Yellow Cab. Rates can be high and quickly add up. Uber is more reasonable.
Houston B-Cycle is good for a quick jaunt about town. Find a B-Cycle station, swipe your credit card and head off on a bicycle (which you can return at other stations). The first hour is included in the membership charge. Download the useful app for full info.