Mexican Federal Highway 1 turns into Interstate 5 at the international border with the United States south of San Ysidro, California. The road is often called the Carretera Transpeninsular or Transpeninsular Highway. Most of its length is two lanes. It has not protections or guardrails and the surface of the road is asphalted. From El Médano to Las Barrancas towns the road, also known as Carretera Transpeninsular, is said to be the longest straight stretch of road in the country: 169km (105 miles) without any turn.
Any barriers along the edge afford little more than token protection; large stretches should be taken at a snail's pace and a lookout kept for vehicles coming from the opposite direction! With the lack of shoulders, guard rails and deficient road signs, this road, officially "Carretera Transpeninsular Benito Juarez", named after one of Mexico's most revered heroes, is extremely dangerous indeed. The road is in dreadful condition and requires strong nerves to negotiate it. It’s certainly breathtaking and it has a fearsome reputation. Shared by freight trucks, oversized RVs and, well, almost every single vehicle on this 1,000-mile-long peninsula, it can get downright hairy, particularly where it twists through the mountains and hugs the coastline between hillsides and sea. Accidents are common and, in many places, guardrails are split open where previous drivers have missed their turns. Construction of this road was completed in 1973. Some vehicles drive very fast, and the main risk on this road is coming around a blind corner to discover a vehicle proceeding toward you at high speed.