Interchange of the Week
Monday, 17 November 2003

I-90 & US 9, Albany

NY 377

A full-size image (586 KB) showing greater coverage is also available.

Orientation: Interstate 90 runs from left to right at bottom, while the US 9 arterial runs from bottom left to top. Loudonville Road enters at bottom right, becoming Albany Shaker Road as it crosses over US 9. A continuation of Loudonville Road runs north along US 9 at top. Van Rensselaer Boulevard runs from Loudonville Road toward top right. Northern Boulevard runs from left toward top right, becoming Lawn Street east of Van Rensselaer Boulevard. NY 377 begins at US 9 on Northern Boulevard, turning northward onto Van Rensselaer Boulevard toward the Village of Menands.

Exit numbers: Exit 6 from I-90 is for US 9 to Loudonville and Arbor Hill (a section of Albany). Exits on US 9 are not numbered.

The interchange: The junction between I-90 and US 9 is a four-level, semi-directional stack interchange, considered the optimal design for full freeway-to-freeway interchanges. (Exit 6A [I-787], immediately to the east, is also such a structure, and the junction between I-295 and the Grand Central Parkway in Queens is the only other four-level stack in New York State.) This design, which resembles a Maltese Cross when viewed from above, features right-hand exits and entrances in all directions, which is preferred by highway engineers. The four left-turn ramps and the two freeways all cross each other in a four-level crossover at the center of the interchange. This particular junction is slightly modified from the pure form: the westbound-to-southbound ramp merges into US 9 independently, rather than first meeting the eastbound-to-southbound ramp. This is becuase of an adjacent railroad overpass.

Another modification is that the stack interchange overlaps a full diamond interchange with Northern Boulevard, marking the southern terminus of NY 377. Notice that the southern ramps of this diamond branch only from the I-90 ramps, so that there is no access between NY 377 and US 9 to and from the south (Northern Boulevard provides these connections just to the southwest). Also, the southbound ramp from US 9 (the divergence point is shown only on the full-size image) acts as a service road to some local streets. Finally, a ramp connects Loudonville Road, on the southeast, to its northward extension on US 9, making the road continuous only in the northbound direction.

Although only this short stretch of US 9 is configured as a freeway, the high-powered stack interchange was used because this was planned to have been the intersection of I-90 and the Mid-Crosstown Arterial. The image at right shows were this freeway would have continued southwestward toward downtown Albany. Today, the lanes of US 9 abrubtly narrow and feed into Northern Boulevard (bottom left corner) at its intersection with Livingston Avenue. The northbound freeway entrance is fed by Northern Bolevard, a short service road, and Colonie Street.