Horizontal Curves, Signs, and Safety

Khan, Ghazan; Bill, Andrea R.; Chitturi, Madhav; Noyce, David A.

doi:10.3141/2279-15

Cited by 29 publications

(15 citation statements)

References 8 publications

(8 reference statements)

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“…Such devices have been evaluated as a speed-and crash-reduction countermeasure across a variety of settings, including school zones (9), work zones (10,11), speed transition zones (9,12,14), sharp horizontal curves (7,9,15), and high-speed arterials (9,13,14,16). Studies have also evaluated the effectiveness of DSFS on driver behavior based on the road geometry (17), sign placement (18), and the message being displayed (19).…”

Section: Introductionmentioning

confidence: 99%

Driver Response to a Dynamic Speed Feedback Sign on Freeway Exit Ramps Based on Sign Location, Interchange Type, and Time of Day

Mahmud

Motz

Holpuch

et al. 2021

Transportation Research Record

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A series of field evaluations was performed at three freeway interchange ramps in Michigan that possessed significant horizontal curvature to assess the impacts of a dynamic speed feedback sign (DSFS) on driver speed selection and brake response while approaching and entering the ramp curve. A DSFS with a 15 in. full-matrix display was temporarily installed at each of the three exit ramp locations. The sign was programmed to display the same feedback message at each location, which included the speed number for all approaching vehicles, which alternated with a “Slow Down” message for vehicles approaching above 40 mph. The effectiveness of the feedback sign was tested across various sign locations (at the point of curvature versus 350 ft upstream), interchange types (system versus service), time of day (peak versus off-peak), light conditions (daylight versus darkness), and vehicle types (passenger vehicles versus trucks). Compared with the pre-DSFS site condition, the DSFS reduced curve entry speeds and improved brake response at two of the three ramp locations. In general, the greatest beneficial effects on driver behavior were achieved when the DSFS was positioned at the point of curvature, during which curve entry speeds were reduced by approximately 2 mph. These findings were consistent between the system interchanges and service interchanges, and across all vehicle types. The DSFS was also found to be most effective during daytime off-peak periods compared with peak periods and at night. Further evaluation of DSFS at additional ramp locations, and considering an expanded set of conditions, is recommended.

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Section: Introductionmentioning

confidence: 99%

Driver Response to a Dynamic Speed Feedback Sign on Freeway Exit Ramps Based on Sign Location, Interchange Type, and Time of Day

Mahmud

Motz

Holpuch

et al. 2021

Transportation Research Record

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“…Crash reduction rates for horizontal curve improvements were determined for flattening curves, widening lanes, widening paved shoulders, adding unpaved shoulders, adding spiral transitions, and improving superelevation (Zegeer et al 1992). There are several factors that can affect safety on curves including signage, pavement markings, and roadside hazards (Labi 2006, Zegeer et al 1992, Khan et al 2012. In a study on rural two-lane roads in Indiana, Labi (2006) found that many of the roads observed had deficiencies in signage and markings.…”

Section: Highway Curvaturementioning

confidence: 97%

“…However, because of the availability of curvature data from UDOT's LiDAR project, this research was able to study the effect of horizontal curve on SPFs. Approximately 25 percent of all fatal crashes in the United States in 2002 occurred on horizontal curves (Khan et al 2012). This does not include crashes that occurred on vertical curve segments.…”

Section: Highway Curvaturementioning

confidence: 99%

Development of Crash Prediction Models for Curved Segments of Rural Two-Lane Highways

Knecht¹,

Saito²,

Schultz³

2016

International Conference on Transportation and Development 2016

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Crash prediction models for curved segments of rural two-lane two-way highways were developed. The modeling effort included the calibration of the predictive model found in the Highway Safety Manual (HSM) as well as the development of Utah-specific models developed using negative binomial regression. The data for these models came from randomly sampled curved segments in Utah, with crash data coming from years 2008-2012. The calibration factor for the HSM predictive model was determined to be 1.50 for the three-year period and 1.60 for the five-year period. A negative binomial model was used to develop Utah-specific crash prediction models based on both the three-year and five-year sample periods. The significant variables were average annual daily traffic, segment length, total truck percentage, and curve radius. The main benefit of the Utah-specific crash prediction models is that they provide a reasonable level of accuracy for crash prediction yet only require four variables.

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“…Z tego względu dużą rolę w projektowaniu geometrycznym odgrywają metody oceny jednorodności dróg. Na podstawie wyników badań opracowano liczne modele prędkości i ryzyka wypadkowego, w zależno-ści od krętości i falistości oraz innych cech drogi, takich jak: długość prostej poprzedzającej łuk w planie, szerokość jezdni, szerokość i rodzaj poboczy oraz wyposażenie drogi w urządzenia brd [5,6,7,8]. Iloczyn stosunku wskaźnika liczby wypadków z rannymi na łuku do analogicznego wskaźnika na prostej oraz stosunku energii kinetycznej pojazdu na prostej do energii kinetycznej pojazdu na łuku stanowi tzw.…”

Section: Problem Bezpieczeństwa W Ruchu Drogowym Na łUkach Poziomychunclassified

Symulacje Numeryczne Stalowej Bariery Ochronnej Na Łuku Drogi

et al. 2017

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W pracy wymieniono pewne czynniki związane z bezpieczeństwem ruchu drogowego, wskazując łuki poziome dróg jako miejsca, gdzie występuje istotna liczba groźnych w skutkach wypadków. W części pracy obejmującej symulacje numeryczne, zrealizowano serię badań spełniających warunki testu zderzeniowego TB11 ze zmiennym promieniem bariery. Oszacowano wpływ zróżnicowania geometrii na parametry bezpieczeństwa.Słowa kluczowe: urządzenia BRD, ruch drogowy, bezpieczeństwo ruchu drogowego, badania numeryczne, zderzenia pojazdów, łuki poziome drogi, metoda elementów skończonych 1. Problem bezpieczeństwa w ruchu drogowym na łukach poziomych

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Horizontal Curves, Signs, and Safety

Cited by 29 publications

References 8 publications

Driver Response to a Dynamic Speed Feedback Sign on Freeway Exit Ramps Based on Sign Location, Interchange Type, and Time of Day

Driver Response to a Dynamic Speed Feedback Sign on Freeway Exit Ramps Based on Sign Location, Interchange Type, and Time of Day

Development of Crash Prediction Models for Curved Segments of Rural Two-Lane Highways

Symulacje Numeryczne Stalowej Bariery Ochronnej Na Łuku Drogi

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