The largest volume in the district courts - criminal summary cases - decreased by a quarter between 2008/09 and 2011/12, but costs rose by $20 million, he said.
In October, the Herald on Sunday revealed the jury trial system was approaching "crisis point" as defendants and victims waited more than three years for some cases to be heard. Bridgman said the department was working hard to improve.
"Since August, we've let people wanting to dispute an infringement notice apply via email rather than go to court or post this in," he said.
"If people see us as timely, efficient and modern, we will also be seen as more reliable and trustworthy," he said.
Bridgman said the email line, monitored by court staff to make spot decisions, had been highly effective, even without advertising or fanfare.
"In the first month, around 40 per cent of applications were filed by email.
"That's a huge, immediate take-up, and 99.7 per cent were processed within 24 hours."
The Herald on Sunday tracked one man's dispute.
The man, who asked not to be identified, incurred three speeding fines in May and June but the infringement notices went to his previous address.
He became aware of the fines only after they had gone to court and an extra $200 in court fees was added.
He was told he could dispute the court fees through the online system and get a response within 24 hours.
Twenty-four hours after applying, he hadn't heard back, but contacted the email line again and was told the court fees had been waived.
Bridgman said the man was one of about 430,000 people with outstanding fines, although the numbers were dropping.
The courts have also introduced an online system for lodging and paying for claims and rehearing applications with the Disputes Tribunal from October 1.
Other improvements include the Criminal Procedure Act coming into effect in July next year, which he described as the biggest overhaul of the criminal justice system in 50 years.
"It will mean 31,000 fewer court events a year, which is about 10,000 sitting hours; and mean that 350 to 500 fewer cases require a jury trial each year," he said.
The justice sector employs around 22,000 people; with an operating budget of $3.8 billion a year, over the next five years it will have a capital spend of $1.8 billion.