The Maximum Legal Speed You Can Travel on the Road in Wet Conditions Is the Speed Limit

After investigating a fatal wet weather crash on Interstate 35 near Hewitt, Texas, on February 14, 2003, the National Transportation Safety Board (NTSB) issued five safety recommendations to the Federal Highway Administration (FHWA) to improve road safety in wet weather. These safety recommendations are as follows: In summary, everyone must be vigilant and attentive when driving a vehicle. This vigilance must be increased in wet and poor conditions. Slowing down is your first line of defense, your second is to return your visibility to other drivers and finally avoid the cruise control feature. Obviously, the deceleration maneuver is influenced by wet roads. A guideline on geometric road and road design (2) recommends 11.2 ft/s2, a comfortable deceleration rate for most drivers, as the deceleration threshold to determine a reasonable stopping distance. This deceleration corresponds to the friction of braking on packed snow and therefore lies in the driver`s ability to maintain control of the vehicle during braking manoeuvres on wet roads. In addition, most vehicle braking systems and the friction coefficients between tires and the road surface on most road surfaces, even in wet conditions, can provide a deceleration of at least 11.2 ft/s2. Footnote 3 Illinois law allows Cook, DuPage, Kane, Lake, Madison, McHenry, St. Clair and Will stepped back by issuing an ordinance setting a lower speed limit and allowing counties to make adjustments based on their own local needs. These counties have a maximum speed limit of 60 mph outside city districts and 55 mph in city districts.

↩ In most cases, establishing a speed zone is based on the assumption that most drivers operate their vehicles safely, reasonably and safely. The speeds chosen by the majority of drivers on a given stretch of road are considered indicative of safe and appropriate speeds. The 85th percentile speed of free-flowing vehicles, the speed at which 85% of drivers travel at or below a certain point on the road, is commonly used to determine the speed specified for this segment. This maximum safety speed set by the driver can then be easily adjusted as needed, based on location-specific factors including visibility restrictions, road conditions, etc. A speed limit at the next level of 5 mph of this maximum safe speed is then usually specified (5, 11). The first thing that stands between you and safety during a wet run is your speed. Speed plays a role in everything when it comes to driving. Typically, you reduce your speed by a third when you`re wet. Calculate; If you drive the speed limit on I-10 to normally get to Houston at 65 miles per hour, you should drive 43 miles per hour in wet conditions. Speed in wet conditions also affects stopping and braking distance. In dry conditions, when traveling at 70 mph, you can expect an average total braking distance between 315 and 320 feet. To put these numbers in perspective, it`s more than the length of two football fields.

Footnote 1 In Hawaii, the speed limit is set by a county order or by the Director of Transportation. ↩ Footnote 5 New Hampshire House Bill 146 of 2013 increased the speed limit from 65 mph to 70 mph on the section of I-93 from Mile 45 to the Vermont border. ↩ Footnote 8 Sections of I-10 and I-20 in West Texas and sections of Highway 45 in Travis County have a speed limit for cars and light trucks of 80 miles per hour. Speed limits of up to 85 miles per hour may be set if the highway was originally built and designed for the higher speed and was deemed reasonable and safe by engineering study. State Highway 130 (partial toll) has a limit of 85 miles per hour. All states take the same basic approach to formulating speed limits. ↩ This approach specifies that drivers must not exceed safe and prudent speeds for existing conditions, even if the specified speed limit indicates that a higher speed is allowed. Thus, the driver is responsible for taking into account the road environment and possible dangers when choosing a speed. These include weather, visibility, traffic and road characteristics (5). Speed causes a lot of accidents. More drivers are convicted of speeding than any other offence. To avoid a fine or be involved in an accident, obey the speed limits.

Footnote 10 In Washington State, speed limits on highways or sections of highways can be set at 75 miles per hour if they are based on a traffic and engineering study that will come into effect in August 2015. ↩ Although the speed limit may be based on the speed of the 85th percentile, many studies have reported that the indicated speed limit is generally significantly lower than the 85th percentile measured. For example, the Institute of Transportation Engineers (ITE) found that for roads with speed limits of 45 mph or less, most measured speeds are above the indicated speed limit (12). If the specified speed limit is 55 mph or higher, approximately half of the measured speeds will be higher than the specified speed limit. This may be partly due to the difficulty of predicting operating speeds (and therefore the speed limit) based on road geometry and road characteristics. Speed is very important in the event of a collision. If you double the speed of a car, you increase its impact force by four times. If you triple the speed, the effect is nine times greater. Wet weather VSL systems should be considered in locations where adverse weather has occurred in the past, accident rates are higher than expected, safe speeds drop more than 10 miles per hour (mph) below specified speed limits, and braking distances exceed available viewing distance. The FHWA`s ENTERPRISE Pooled Fund Study provided four mandates to consider when using regulatory VSL systems (3). While the ENTERPRISE Mutual Fund Study suggests that optimizing capacity and safety in the work area are two reasons to consider VSLs, there are also guarantees of safe braking distance and driving speed in adverse weather conditions.