The mayor of the city of Lhokseumawe told the Jakarta Globe Wednesday that the new regulation was to protect women’s morals: "We've seen that people's behaviors and morals are getting far from Aceh's Islamic cultural values."
Under the new decree, women passengers are required to “side-saddle” behind the male riders.
Aceh, which has a special autonomy status, is the only Indonesian province that follows Sharia.
"We want to save women from things that will cause them to violate Sharia law. We wish to honor women with this ban, because they are delicate creatures," Mayor Suaidi Yahya told the Globe.
"When you see a woman straddle, she looks like a man. But if she sits side-saddle, she looks like a woman," Suaidi said.
He added that the passengers who sat side-saddle rarely fell off the vehicles.
Suaidi said his administration had started distributing handouts to government offices and villages throughout the municipality to inform the local residents of the new policy before the plan would formally implemented in a few months.
He added that the new regulation was likely to discourage women from wearing pants in public: “It will be easier for women to avoid straddling motorcycles if all of them wear skirts.”
“There will be sanctions for those who violate [the regulation],” he added, without naming the sanctions.
The proposed ban has sparked widespread criticism, leading to the central government seeking clarification from the local government with regard to the decree.
Home Affairs Ministry spokesman Reydonnyzar Moenek told CNN Friday that "the proposed regulations need to be clarified and evaluated by the Home Affairs Minister before the local government can issue it as a decree."
"There have been criticisms that the proposed decree is discriminatory and has a gender bias," said Reydonnyzar. However, he added that local regulations should reflect the local culture, traditions and aspirations of citizens.
In December 2011, Aceh’s police detained dozens of young men and women for being “punk,” drawing criticism from rights groups.
In October 2009, the women in West Aceh were banned from wearing tight trousers or jeans. Violators were required to change into a free government-issued skirt while their trousers were cut up.
The same year, Aceh's provincial government passed a law which made adultery punishable and the culprits would be stoned to death. The law also imposed severe sentences for rape, homosexuality, alcohol consumption and gambling.