Speed bumps require legal gazetting and once approved by the Town, the Ministry of Works and various other departments they can be installed. As with everything, permission takes time to be approved and actual installation is not only time consuming but also costly. So to answer WWIII's question, I imagine it took government applications, time and money on Grand Caribe's part in order to obtain permission to install the bumps. Indeed as Roberto mentioned, the larger resorts paid to ensure that the roads through their properties were installed correctly and, in the case of Belizean Shores, it also included pretty medians that the resort cares for.