The 101 Freeway is a superhighway running through the Mega City in the Matrix. A very dangerous stretch of road, it is patrolled heavily by police and Agents, seeking any Resistance members who dare to drive on it while trying to escape.
In The Matrix Reloaded, Trinity and Morpheus attempt a daring escape from deep inside the Core Network along the 101. Trinity, driving the getaway car, mentions that Morpheus had warned her repeatedly not to take the roadway because of the extreme hazard involved. Morpheus replies "Then let us hope I was wrong" and orders his operator, Link, to direct them to the nearest entrance. Link obeys but tries to warn his captain of the danger involved -- he is immediately interrupted by Morpheus and agrees to follow orders.
With The Keymaker in tow, the two enter the freeway and are immediately set up on by multiple police and Agents on station and by The Merovingian's Twins, who have pursued the heroes from their boss' mansion inside the Core Network. Trinity is able to evade their pursuers with The Keymaker while Morpheus battles with the Twins and an Agent in hand-to-hand combat that nearly kills him. When a stranded Neo is able to find his way from the mountains south to the 101, he rescues Morpheus and The Keymaker from certain death when two Agents slam two semi-trucks head on in a massive collision.