That could be one explanation for the popularity of the I-95 Express Lanes, called Lexus Lanes by opponents because of the toll paid by solo drivers. While the toll has increased, so has their popularity with drivers, even with the maximum $7 toll.
Jan 2, 2014 WLRN
Opponents of High-Occupancy-Toll lanes have long claimed that these lanes, often converted from High Occupancy Vehicle lanes like Miami's I-95, would encourage solo-drivers, especially wealthier ones, to pay to use the express lanes.
Jan 23, 2010 Streetsblog San Francisco