Grade separation in practice

Here's a rare example of a grade-separated intersection of two four-lane major streets. It is located in Haifa, Israel, at the intersection of Hankin Road and International Street. Haifa is Israel's third largest city (2003 population: 270,000). The neighborhood surrounding this intersection is mixed use commercial and residential, and is rather similar to what we have at Genesee Avenue and Governor Drive. There are other correspondences as well: both roads are four lane major streets. Road topography, parking, and pedestrian access are also similar. The peak hour volume at this intersection (last measured in May, 2002) was 3,914 vehicles per hour (vph). This is comparable with the corresponding number for Genesee/Governor of 4,914 vph.

According to Mr. Doron Magid, a traffic engineer with the municipality of Haifa, the underpass was constructed in situ in 1993, without shutting down the daily flow of traffic. The underpass has low clearance (2.9 meters = 9.5 feet), and does not admit high profile vehicles, such as buses. It is somewhat smaller in scale as compared with what is planned for Genesee Avenue and Governor Drive (underpass clearance 14.5 feet). Still, the images below are illustrative of this suburban application of grade separation.

Westbound vehicles on Hankin (upper left panel) may continue through the intersection at grade, or may pass through the underpass by merging into the left through lane. The western end of the grade separation is shown in the upper right panel. The outer at-grade through lanes, which are depleted of traffic, merge seamlessly with the interior grade separated lane. The profile of the grade separation, when viewed from the side (lower left panel), is rather unobtrusive. Finally, the big payoff: the intersection is congestion-free (lower right panel). Pedestrian walkways and modest landscaping add to the safety, convenience, and attractiveness of this intersection.

(Click here to see the detailed intersection summary.)