Here at Grapevine, a small section of concrete is visible adjacent to the southbound lanes of I-5. This is a section of former US 99. A small color difference can be noticed between the two lanes that are visible. This difference is due to age. The lanes to the left were constructed in 1932 when Grapevine Grade was realigned, bypassing the original 1914 Ridge Route grade. This was built as two lanes as a temporary measure to expedite the opening of the new route. Right after it was opened, a third lane was added, the lane on the right, creating a three-lane roadway with a common passing lane in the center, or “suicide lane”. This condition persisted until 1943 when the road was widened yet again to four lanes. In 1959 – 1960, these lanes were bypassed by the current southbound lanes of I-5. Today, they remain as one of the last remnants of the 1932-1959 version of Grapevine Grade.
