Prof Lineham said Gloriavale's elders had for some time been seeking to further cloister the community. He said the road closure would create another impediment for members wishing to leave Gloriavale.
"Remember that's the road along which people who've escaped have generally been picked up from."
He claimed local authorities would not oppose the road's closure.
"It's in the council's interests to close the road because they don't have to do any upkeep on it."
Prof Lineham said Gloriavale was in fact quite integrated with the West Coast economy, even though employment at the commune's enterprises was limited to church members.
The professor said banality and drudgery probably typified most aspects of life inside the compound. "What goes on inside is probably mostly incredibly boring, very heavy regimentation of all aspects of life."
Prof Lineham told Newstalk ZB the group was unique in New Zealand, and had an interesting history.
"They tried to convert me when I was a boy at school."
He declined the offer.
An estimated 22 people have left Gloriavale in the past two months.
A woman known as Julia said she was shunned and banished after leaving the community about three years ago.
"I felt like I was getting suffocated. I needed to be myself," she said on Campbell Live last night. "We're told that the outside world's evil, nobody loves us."
Contacted this morning, a Gloriavale member said nobody was immediately available to comment but to call back later.
The church's doctrines were published on its website and included views on sin, forgiveness, discipleship, baptism and God's judgement.
"Despite what humanism may teach, the nature of mankind is not to do good, but to do evil," the church said.
The group, which convicted sex offender Neville Cooper founded, said it was tolerant of other churches.
"The Church at Gloriavale is one local Church in the whole body of believers, wherever they may be. We recognise that not every assembly of Christians has the opportunity to live as we do, and nor may they have the same understanding of God's Word that we have."
Only men could become leaders in Gloriavale. Members adhered to a dress code including blue dresses and head coverings for women.
The group was the focus of the TV2 documentary Gloriavale -- A World Apart which screened last year.
It was also revealed this month that most Gloriavale members weren't aware of their leader's indecent assault conviction and previously believed he was jailed for preaching the gospel.
Elijah Overcomer told NZME. News Service he was evicted after questioning Cooper over the 1994 conviction and 11-month jail term.
"Most people in there believe that it's because he was preaching the gospel. So everyone says, 'oh, evil people put him in jail because he preached the gospel'," Mr Overcomer said.
