Further routes were developed during the following years authorised by the passing of Parliamentary Acts and Orders of 1876, 1877, 1879, 1881, 1883, 1887, and 1896.
As part of the long running trading war between the horse buses of Solomon Andrews in Cardiff and the Provincial trams in Cardiff the Andrew's buses were also deployed in Plymouth and Portsmouth to compete with Provincial in its other towns.
When this conflict, which started in 1872, was resolved in 1887 the horse bus operations of Solomon Andrews were purchased by Provincial and those in Portsmouth were merged with the horse bus routes operated by the Portsmouth Street Tramways Company.
The purchase price had to be settled by arbitration at £185,633 which was unfortunate for the company because they had declined an offer from the Corporation of £205,964.
After surviving an attempted takeover by Gosport and Alverstoke Council the company went on to reconstruct and electrify the tramways and extend the Brockhurst branch to Fareham Railway Station in 1905.