The wall will do that quite nicely. One of the reasons that border patrol officers don't want the wall is that it blinds them. With a fence, they can quickly scan a lot of territory, even while patrolling by vehicle. A wall takes that away.
What Border Agents Say They Want (It’s Not a Wall)
The report was based on internal Customs and Border Protection documents from the 2017 fiscal year. It concluded that less than one half of 1 percent of the agents’ suggestions to secure the Southwest border mentioned the need for a wall.
Senator Claire McCaskill of Missouri, the committee’s top Democrat, said the report reinforced what she had previously heard from border agents and leaders at Customs and Border Protection, the parent agency of the Border Patrol.
“We can’t let politics get in the way of our efforts to strengthen border security and protect our country,” said Ms. McCaskill, referring to Mr. Trump’s promises to build a border wall.
https://www.nytimes.com/2018/03/22/...-wall-immigration-trump-senate-democrats.html
And most Mexicans don't travel on foot or by burrow anymore. So you hire someone to drive out to the wall, extend the ladder, tie the rope to the top, and you go down the other side. The ladder and rope can be used by multiple people very quickly, and then taken down and away by the coyote for the next night.