A traffic accident in which four Chinese tourists died in Arizona on Sunday has raised concerns about the safety of overseas travelers when they take to US roads.

The accident occurred on state Route 93 at the intersection with Pierce Ferry Road outside the town of Dolan Springs, when a van, turning left onto Pierce Ferry Road, collided with a bus carrying staff members of the Dallas Cowboys pro football team traveling in the opposite direction, according to the Arizona Department of Public Safety.

The van's driver, Li Guangxiang, 52, and three female passengers, Ou Suiqing, 52, Bi Sangqin, 52, and Li Yuetong, 19, died at the scene. They were all from Guangdong province in South China and visiting the United States, according to the latest information from the department.

The four Cowboys staffers on the bus were not injured in the collision.

The investigation determined that the van failed to yield the right-of-way at a stop sign and was struck by the Cowboys bus. All van occupants were wearing seat belts at the time of the crash, the department said in a statement on Tuesday.

It also said the investigation is ongoing, and an inspection of the bus will be performed by the department's commercial vehicle inspectors.

A Los Angeles-based lawyer raised questions over the department's conclusions about the accident, saying those involving fatalities usually require months of investigation to determine fault.

Daniel Deng, who said he has assisted many Chinese tourists and students with major auto accidents throughout the US, told China Daily in an email that many people were "outraged when the Arizona Public Safety Department concluded that the accident was caused by the Chinese driver only one day after the accident".

"Traffic accident investigators will have to investigate the integrity of the vehicle, i.e., checking the brakes, determining how fast the bus was going, as well as determining the well-being of the bus driver, (which) are all important factors that must be considered when giving judgment," Deng said.

"In addition, an autopsy report is obviously needed for an accident that involves the deaths of human beings, and that itself would require at least a month before results come out," he said, adding that the department's determination showed "sloppiness" and "inconsiderate work and effort".

Self-driving tours have become popular among Chinese tourists. Many tourism agencies in China promote routes such as California Highway 1, the Grand Canyon and some national parks.

"The biggest challenge for Chinese self-driving tourists is the language barrier and lack of knowledge of local traffic rules," said Forrest Lin, a Guangzhou-based tourism operator in an earlier interview.

Chinese tourists traveling overseas have been involved in tragic accidents recently. A tour bus rolled over, killing a Chinese tourist and injuring three more last month in Alexandria, Virginia. Another tour bus accident killed 26 last week in Taiwan after it caught fire on a highway.

As more Chinese travel internationally, their involvement in accidents also has risen, said Zha Liyou, Chinese deputy consul general in San Francisco.

Last year, around 4.7 million to 4.8 million people traveled between China and the US, and the number is expected to exceed 5 million this year, he said.

liazhu@chinadailyusa.com