Enrique Gonzalez-Velez Civil and Environmental Engineering University of South Florida
Background Objective Introduction Roadway Lighting Literature Review Study Area Data Illuminance, Crash, and Roadway Future Work Acknowledgements
2007 Nationwide Data 37,248 fatal crashes occurred in the USA 36% occurred during dark condition (non present of astronomical light - 9:00 p.m. to 6:00 a.m.) In Florida reports show 2,943 fatal crashes 8% of the nationwide fatalities 40% respectively occurred during dark period FARS Encyclopedia. USDOT and NHTSA: http://wwwfars.nhtsa.dot.gov/main/index.aspx
Nationwide Fatal Crashes Florida Fatal Crashes 39,500 39,000 38,500 38,000 37,500 37,000 36,500 36,000 35,500 35,000 34,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 0 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 FARS Encyclopedia. USDOT and NHTSA: http://wwwfars.nhtsa.dot.gov/main/index.aspx
To find out the relationship between nighttime accidents and street illuminance lighting levels. This includes the analysis of crash data and the illuminance level measured.
Nighttime traffic accident rates are considerably higher. Only approximate 24 percent of the vehicle-miles traveled occur at night (Florida 24 hr counts data). Many research indicates a significant reduction in the number of crashes when roadway lighting is installed.
Roadway Lighting main objectives: supplement vehicle headlights, extending the visibility range beyond their limits improve the visibility of roadway features and objects on or near the roadway delineate the roadway ahead crime reduction traffic safety
Different methods: Luminance Small Target Visibility (STV) Illuminance
Used to evaluate lighting design Measure the reflectance of the roadway surface Inappropriate for the evaluation of lighting system
Source: AASHTO Roadway Lighting Design Guides (2005)
Source: AASHTO Roadway Lighting Design Guides Appendices (2005)
The total amount of visible light illuminating a point on a surface from all directions above the surface. This "surface" can be a physical surface or an imaginary plane. Standard units: Lux (lx) (lm/m 2 ) Footcandle (fc) (lm/ft 2 )
Source: IESNA Guide for Photometric Measurement of Roadway Lighting Illuminations (LM-50-99)
Author & Year Summary Findings Box (1972) Walker (1976) Present the findings of a study in were the relation between freeway accident and illumination level was analyzed. Accident frequency for rural at grade intersections was determined for 3 years periods immediately before and after lighting. Box (1976) Before and after study on 2.5 miles State Highway 60, Gulf to Bay Boulevard, Clearwater Florida. In this study lamps were turned off. An Average reduction of 40% on nighttime accidents was found as a result of lighting. Rate of accidents was reduced from 1.89 to 0.91 accidents/mev, representing a 52% reduction. In general, lighting significantly reduced the number of night accidents at ADT levels above 3,500. Before Gulf-to-Bay had 20% on night accidents, and after reduction on light had 25% (5% Increase)
Author & Year Summary Findings Elvik (1995) Analysis of 37 studies containing 142 results evaluating the safety effects of public lighting. Monsere (2008) 44 interchanges and 5.5 miles of interstate freeway were modified Interchanges from full lighting to partial, interchanges from partial plus design to partial lighting configuration, and interstate freeway mainline lineal lighting was reduced. Safety effects of roadway lighting was found as; a 65% reduction in nighttime fatal accidents, a 30% reduction in nighttime injury accidents, and a 15% reduction in nighttime property-damage-only accidents. The most robust finding of the analysis is that there was a rather significant increase in total and injury night crashes for lineal sections. The analysis found an increase in total night crashes at interchange locations and a decrease in injury night crashes at these same locations.
Author & Year Summary Findings Wanvik (2009) This study estimates the safety effect of road lighting on accidents in darkness on Dutch roads, using data from an interactive database containing 763,000 injury accidents and 3.3 million property damage accidents covering the period 1987 2006. The mean effect of road lighting on injury accidents during the hours of darkness is 50% [ 53%, 47%]. The estimated effect of road lighting on injury accidents during darkness on rural roads is 54% [ 56%, 52%]. The average increase in risk with respect to pedestrian accidents is 141% on lit roads and 361% on unlit roads (rural).
ID Roadway ID Road Name Length County Begin-Street End-Street 1 2010000 US 41/SR 44 1.500 Citrus Relief St Davidson Avenue 2 2030000 US 19 3.211 Citrus SE 8th Avenue NW 22nd St 3 8010000 US 41 3.386 Hernando SR 50 Lakeside Dr 4 8040000 SR 50 2.556 Hernando SR 50 US 98 5 10005000 40th St 2.845 Hillsborough Adamo Dr E E Hillsborough Avenue 6 10020000 Florida Avenue 11.211 Hillsborough SR-60 Kennedy Blvd Nebraska Avenue 7 10030000 Hillsborough Avenue 4.772 Hillsborough Nebraska Avenue Orient Rd 8 10030000 US 92 Reynolds St 2.454 Hillsborough Thonotosassa Rd Park Rd 9 10030101 US 92 Baker St 1.782 Hillsborough Reynolds St Thonotosassa Rd 10 10040000 Nebraska Avenue 8.164 Hillsborough Kay St 142nd Avenue 11 10060000 US 41 12.117 Hillsborough 1st St SW Riverview Dr 12 10080000 Kennedy Blvd 1.686 Hillsborough Henderson Blvd Brevard Avenue 13 10110000 E Frank Adamo Dr 6.970 Hillsborough N 22nd St I-75 14 10130000 Dale Mabry Hwy 7.181 Hillsborough Gandy Blvd Hillsborough Avenue 15 10140000 Courtney Campbell Cswy 5.012 Hillsborough Pinellas County Line Rocky Point Dr 16 10150000 Hillsborough Avenue 7.803 Hillsborough Theresa Rd Nebraska Avenue 17 10160000 Dale Mabry Hwy 9.485 Hillsborough Hillsborough Avenue Veteran Expressway 18 10250000 22nd St 2.782 Hillsborough N21st St Hillsborough Avenue 19 10250101 21st St 0.622 Hillsborough I-4 Adamo Dr 20 10270000 Kennedy Blvd 1.980 Hillsborough Ward St Henderson Blvd 21 10290000 Fowler Avenue 5.454 Hillsborough Florida Avenue Morris Bridge Rd 22 10310000 Busch Blvd 3.530 Hillsborough Nebraska Avenue 56th St 23 10330000 56th St 6.023 Hillsborough E21st Avenue Fowler Avenue 24 10340000 MLK Jr. Blvd 10.550 Hillsborough Dale Mabry Hwy Queen Palm Ave 25 14030000 US 19 11.105 Pasco Phoenix Avenue Gulf Highlands Dr 26 15007000 S. Missouri Avenue 3.041 Pinellas East Bay Dr Court St 27 15010000 5th Avenue N/Tyrone Blvd/Seminole Blvd 17.066 Pinellas 4th St N East Bay Dr 28 15020000 Alt US 19 5.271 Pinellas Myrtle Avenue Orange St 29 15030000 East Bay Dr 6.627 Pinellas Seminole Blvd Ulmerton Rd 30 15040000 Gulf to Bay Blvd 4.715 Pinellas Highland Blvd Damascus Rd 31 15050000 Drew St 6.792 Pinellas N Myrtle Avenue Delaware St 32 15100000 Gulf Blvd 7.858 Pinellas Pinellas Bayway SR 666 33 15110000 Passadena Avenue 1.775 Pinellas Blinds Pass Rd Park St 34 15120000 Ulmerton Rd 11.828 Pinellas Gulf Blvd I-275 35 15140000 Gulf Blvd 6.752 Pinellas SR 666 Walsingham Rd 36 15150000 US 19 30.962 Pinellas 54th Avenue S Live Oak St 37 15240000 Gandy Blvd/4th St 5.883 Pinellas US 19 I-275 Total 242.751miles
Two-lanes undivided highway with fixed roadway lighting at one side
Four-lanes divided or undivided highway with fixed roadway lighting at two sides
Six-lanes divided highway or more with fixed roadway lighting at two sides
Roadway Classifications Interstate, Expressway, Freeway & Major Arterials TABLE 7.3.1 Illumination Level Average Initial Horizontal Foot Candle (H.F.C.) UNIFORMITY RATIOS Avg./MIN. MAX./MIN. 1.5 4:1 or Less 10:1 or Less All Other Roadways 1.0 4:1 or Less 10:1 or Less Pedestrian Ways & Bicycle Lanes 2.5 4:1 or Less 10:1 or Less Plans Preparation Manual, Volume 1 English (January 1, 2009)
9.00 Left Outer Left Inner 8.00 Illumination Level (fc) 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 13.520 14.020 14.520 15.020 15.520 Milepost 16.020 16.520
9.00 Right Outer 8.00 Illumination Level (fc) 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 13.520 14.020 14.520 15.020 15.520 Milepost 16.020 16.520 Right Inner
Florida CARS System Day time / Dusk / Down Nighttime with lighting Nighttime without lighting Sunrise and Sunset data From U. S. Naval Observatory
12:00 AM 1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00 AM 11:00 AM 12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00 PM 11:00 PM January February March April May June July August September October November December Dawn Day Dusk Night
Accident location (milepost) Date (day/month/year) Day of week Time (hour) Accident severity (F/I/PDO) At intersection Intersection-related Driveway-related At railroad highway grade crossing Grade-crossing-related Speed-change lane Not related to junction Light condition Weather Pavement surface condition Number of vehicles involved Driver age Vehicle types involved First harmful event Most harmful event Object struck Ran-off road indicator (yes/no) Pedestrian indicator (yes/no) Bicycle indicator (yes/no)
Beginning and ending points - linkable to accident data Area type Number of lanes and width Auxiliary lanes (TWLTL/passing lane/other auxiliary lane) Median type and width Shoulder type and width Average daily and hourly traffic Percent heavy vehicles Posted Speed
Pair the crash data with the illuminance levels to perform an analysis to identify if exist a direct relationship. Identify the average illuminance level that is more appropriate.
This project was sponsored by the Florida Department of Transportation District 7 Jiguang Zhao
Enrique Gonzalez-Velez Graduate Research Assistant Center for Urban Transportation Research University of South Florida 4202 E. Fowler Avenue, CUT 100 Tampa, FL 33620-5375 E-mail: egonzal@cutr.usf.edu