Existing Conditions

I-81 was built in Onondaga County during the 1950s and 1960s. Portions of I-81 are nearing the end of their lifespan. In particular, it is the deteriorating condition of the 1.4-mile elevated section of the interstate in the City of Syracuse (the viaduct) that is the primary motivation for studying the future of I-81 at this time.

As part of The I-81 Challenge, a draft technical memorandum has been prepared which analyzes the physical conditions of I-81. This analysis is the first of a series of documents that will comprise the I-81 Corridor Study. The purpose of the Corridor Study is to:

• Collect data to identify the condition of the Syracuse region’s transportation system and the environment in which it operates, focusing mainly on I-81; and,

• Identify potential solutions that are worthy of detailed evaluation.

Key Findings

Here are just a few key findings from the analysis of physical conditions along the I-81 corridor. See the Resources box to preview the report highlights or click here to access the draft summary document, draft full report, and appendices. A hard copy of the report is also available at Onondaga county Central Library located at 447 South Salina St. in Syracuse, NY 13202. If you have any questions or comments regarding these documents, please send them to contactus@theI81challenge.org.

Safety
Accident rates in the many sections of I-81 are relatively high when compared to statewide averages. This is especially true in the area around the I-81/I-690 interchange where accident rates reach five times the statewide average. The accident rate on the northbound viaduct section of I-81 is also more than three times the statewide average. Due to its tight curves and narrow shoulders, large portions of the viaduct are difficult for emergency responders to access.

Capacity
I-81 generally has sufficient capacity for existing traffic volumes north and south of the city.  However, in portions of the corridor, particularly near downtown, it is nearing or exceeding its design capacity during the peak hours.The average speeds in these areas are well below posted speed limits during morning and evening rush hour and any disruption due to maintenance or accidents can cause severe traffic congestion.

Highway Design
When I-81 was constructed in the 1950s and 1960s, highway design standards were different from today.  Although the highway met the design standards of its era, I-81 does not meet current standards for high-speed freeways.  This is true particularly near downtown, where physical constraints forced engineers to design the highway with tight curves, narrow lanes, short weaving distances, and minimal shoulders.  These sections of I-81 generally coincide with areas of increased congestion and high accident rates.

Regional Interstate Through Traffic
Although I-81 is an important national trade route, recent data collection found that only about 12% of all vehicles traveling on the interstate system pass through the Syracuse region. This information is useful for understanding how much traffic is using or could use alternative interstate routes to bypass the region and suggests that diverting regional interstate through traffic will have little impact on traffic volumes or operations on I-81.

Structural Issues
The major reason for the urgency of this effort is the condition of the viaduct and other bridges located on I-81 between the I-481 interchanges, as well as on I-690 in the vicinity of the I-81/I-690 interchange. Of the 76 bridges in this area, 60% are considered functionally obsolete and have narrow lanes, no shoulders or low clearances. Another 9% are in need of rehabilitation, are restricted to light vehicles, or are subject to closure. NYSDOT frequently inspects these bridges and makes routine repairs to protect the traveling public. However, it is critically important to begin a serious effort to address these pieces of infrastructure to assure the safety and efficiency of the future regional transportation network.