The groups are looking for volunteers with cars that can conduct the simulation from 9:30 to 10:30 a.m. Friday on Pu'unene and Ka'ahumanu avenues and surrounding areas.

A sign-waving rally will be held at the same time along Ka'ahumanu Avenue.

Irene Bowie, executive director of Maui Tomorrow, said she hopes to get 220 cars to participate to illustrate the average number of cars that could be departing on and disembarking from the Superferry when it arrives at Kahului Harbor daily. The Superferry is designed to carry 200 passenger vehicles and up to 15 large trucks.

The demonstration will also have volunteer pedestrians to simulate passengers getting off and on the ferry as part of the demonstration on Friday, Bowie said. The 340-foot-long Superferry will carry up to 900 passengers.

"We want to make it close to what it will be like as possible," Bowie said.

"We think it's important for Maui residents, visitors and our lawmakers to understand the impact of this extra traffic on Ka'ahumanu Avenue each day," said Greg Kaufman, president of the Pacific Whale Foundation.

Hawaii Superferry officials said Thursday that they have delayed the July launch of the vessel for at least a month as it is still undergoing Coast Guard inspections at its manufacturer's site in Mobile, Ala.

"The Alakai is the first vessel of its kind that is being built in the U.S. by Austal. An important requirement for Alakai's entry into service is the completion of the United States Coast Guard's detailed certification and inspection process, which is in its final stages in Mobile," said John Garibaldi, president and CEO of Hawaii Superferry.

Improvements to accommodate the arrival of the vessel are under way at harbors on O'ahu, Kaua'i and Maui. At Kahului Harbor, the state Department of Transportation is installing a massive barge on the end of Pier 2 that will serve as a loading ramp for vehicles getting off and on the Superferry.

Ferry service will commence with a daily roundtrip between Maui and O'ahu and a six-day-a-week service between Kaua'i and O'ahu. A second ferry is scheduled to begin service in 2009, providing roundtrips to the Big Island.

According to the Hawaii Superferry schedule filed with the state Public Utilities Commission, the ferry will arrive in Kahului at 9:30 a.m. daily and depart for Honolulu at 11 a.m.

The departure area for passengers and cars will be at the end of Pu'unene Avenue across from the First Hawaiian Bank Kahului branch.

For the traffic simulation, Bowie said the cars that participate will travel up and down Pu'unene Avenue to demonstrate departing and arriving traffic. Cars will also travel on Ka'ahumanu Avenue to turn onto Pu'unene Avenue to simulate other traffic heading to the Superferry dock.

Bowie said she has notified police, fire and other emergency responders and the Mayor's Office of the plans for the simulation.

Maui Tomorrow was among parties filing a suit in 2nd Circuit Court asking that the Department of Transportation be required to prepare an environmental impact statement for Kahului Harbor improvements to accommodate the Superferry. While Judge Joel August initially denied motions to require an EIS, he has taken notice of projects implemented by the state to accommodate the Superferry that were not included in the DOT's arguments against a need for an impact statement.