Buses are used far more frequently and if the weather is dry enough there are buses which travel from Rurrenabaque taking about 16 hours for the journey, but if in the wet season, the same journey can take about a week. In any event you will pay the fare of about 140 Bolivianos.
Travel to and from La Paz will cost 180 Bolivianos and take anything up to 36 hours to cover the distance, while the much nearer location of Guayaramerin will cost much less to cover the 3 hour time distance.
You can forget about trams and buses for traveling around Riberalta. The only types of transport are the ubiquitous motor powered tricycles which usually charge about 4 Bolivianos to ride to any part of the town. All you need to do is flag down the trike and bargain with the driver as to the place you want to visit.
You can take the chance of renting a motorcycle for the day at reasonable price, but the roads are so deeply pot holed that it is hardly worth the while. Take care if you visit the waterfront as invariably you will be asked to present your identification documents by the local police, and a smiling face accompanied by an outstretched hand is not uncommon.