Two parents said they felt more stressed than their child who is taking the National College Entrance Exam this year in Beijing.

A record 12.91 million students around China are expected to take the exam, known as gaokao, which starts on Wednesday and will last two to four days, depending on location.

As one of the most-watched exams in China, it can add pressure to already busy rush-hour traffic in mega-cities like Beijing.

Gao Xiong, a Haidian district-based police officer, said police staffers have been sent to traffic-clogged areas such as schools as part of the city's service for its about 520,000 student candidates.

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