Championship organisers have announced testing regulations for the 2017 Verizon IndyCar Series season, highlighted by four open tests during the season but an overall reduction in the amount of in-season testing.

The seriesR will conduct open tests at Phoenix International Raceway (10-11 February), Barber Motorsports Park (21 March), Gateway Motorsports Park (2 May) and Sonoma Raceway (14 September), the latter coming in the same week as the 2017 season finale.

"We collaborated with all of our teams on the 2017 testing regulations with the goal of minimising the amount of in-season testing," said IndyCar president of competition and operations Jay Frye. "The majority of testing will take place at a series of open tests, which have been strategically routed to coincide with our race schedule. As we finalised our regulations, the focus was on making our test schedule more efficient and minimising the overall demands on the crews during the year. We're confident that this is a positive step forward for the Verizon IndyCar Series."

The in-season testing window runs from 11 April-17 September next year, with teams permitted one test day - in addition to open tests - within that timeframe. The off-season testing window for the 2017 Verizon IndyCar Series season begins on 3 October, with teams permitted three test days between the start of the window and 6 April 2017, which allows teams to utilise the break between the season-opening Firestone Grand Prix of St Petersburg and Toyota Grand Prix of Long Beach.

Teams may earn additional test days - to a maximum of four - by running a rookie driver for the season, one day for running a current Indy Lights driver or operating an Indy Lights team under the same ownership as the Verizon IndyCar Series team. New teams entering the Verizon IndyCar Series would also be allowed up to four additional test days.

Tyre testing comes at the request of Firestone, the official supplier to the Verizon IndyCar Series. Any tyre test is limited to two days, either in-season or off-season, with no more than two teams participating. All teams are permitted to have one car conduct team testing during an in-season tyre test. Engine testing for Chevrolet and Honda is limited to two days for each manufacturer in the off-season window.