In the early 1800s, you had two choices if you wanted to travel between Honolulu and Windward O'ahu.
You could take a canoe trip around the southern end of the island or hike over the steep cliffs of the Ko'olau mountains. The pali (cliff) trail was the quickest and most direct route, but it was very steep and slippery. Hawaiians travelled the trail with ease but foreigners had a very different experience:
"The pass was almost too fearful to be enjoyed. I suffered from apprehension lest I should fall from the rocky steep. I took off my shoes and by setting my feet in the crevices of the rock, I worked myself along, assisted by a native, who saw nothing to wonder at by my awkwardness and fear on passing this grand highway."
Reverend Reuben Tinker, 1831
The foot trail was well travelled by people carrying containers of poi, bundles of taro and sweet potatoes, pigs, chickens, and goats to sell in Honolulu.
In 1897, a new carriage road was built below the existing trail. Portions of the cliff were blasted to create a 20 foot wide road supported by stone walls. The road now would around the mountain.
In 1845, the crowed and dangerous path was paved with stone and widened to six feet. Travel to Honolulu on horse or mule took about 3 hours.
Horse and Buggy
A strong wind struck travelers at every turn and for safety, a wooden railing was added. The road was crowded with horse and mule pulling wagons of sugar, bananas, rice, and fish to market in Honolulu.
The carriage road handled the transition to car with little change until the 1950's. The construction of the four-lane highway we travel today included excavation of the tunnels. This highway was completed in 1957.