90,000 VPD on the six-lane portion west of New Haven, the turnpike carried 75,000–100,000 VPD east of New Haven, and 130,000–200,000 VPD between New Haven and the New York state line as of 2006. There were dozens of plans discussed to alleviate traffic congestion and improve safety on the turnpike for nearly 30 years, but most of these plans languished amid political infighting and lawsuits brought on by special-interest groups. Still, traffic and deadly accidents continued to increase each year on the turnpike, and by the 1990s the Connecticut Turnpike had started to become known as "the Highway of Death". Furthermore, while most of the turnpike is signed as I-95 or I-395, the highway was designed and built before the Interstate Highway System was established. As a result, much of the turnpike does not meet Interstate standards, particularly with overpasses ranging from ; Interstate Highway standards require of vertical clearance. Interchanges are too closely spaced; ramps and acceleration-deceleration lanes need to be lengthened. In some areas, median and shoulder widths and curve radii also fall short of Interstate standards. Complicating efforts to upgrade the turnpike to Interstate standards is that engineers did not acquire enough right-of-way to accommodate future expansion when the Connecticut Turnpike was built during the late 1950s, which means adjacent land must be seized to upgrade the turnpike, resulting in lengthy and costly eminent domain battles between the State of Connecticut and landowners refusing to give up their property. Additionally the turnpike passes through areas with some of the highest property values in the country, making land acquisition for expanding the highway extremely expensive. Finally, the turnpike was built through environmentally sensitive ecosystems and wetlands associated with Long Island Sound, meaning most expansion projects require lengthy environmental impact studies that are able to withstand constant litigation by environmental groups. Air pollution laws also cause conflict, since Connecticut is grouped into the federal statistical areas around New York City and it suffers from consequences and special regulations applied to non-compliant air quality areas. An example of this is that it is easier to lengthen an entrance or exit ramp than to add a full lane, since adding any capacity to a road, by definition, will increase the pollution created by the road, further violating federal air quality standards. In 2000, one ConnDOT official commented during a public meeting on expanding I-84 (an Interstate that parallels I-95 about further