Maryland may eventually do away with tollbooths on the state's highways, bridges and tunnels and switch to electronic toll collection. A preliminary report by the Maryland Transportation Authority concluded that converting its seven toll plazas is feasible but would cost as much as $180 million. Transportation officials initiated the study as they look for long-term savings and ways to reduce travel time and increase highway safety. "It's something we're interested in doing. It's something the industry is moving toward. But it's complicated and we're in the earliest stages," said Harold Bartlett, the transportation authority's executive secretary. At least eight states...