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I1 APPENDIX I LIGHT VEHICLES AND BUSES SUMMARY TABLE OF CONTENTS LIGHT VEHICLE RESULTS ................................................................................................... I2 Northern California Sites .................................................................................................. I2 North Carolina Test Sites ................................................................................................. I5 Test Site Summary .............................................................................................. I9 BUS RESULTS ..........................................................................................................................I10 Test Site Summary .............................................................................................I12
I2 LIGHT VEHICLE RESULTS Light vehicle data were taken at three sites in Northern California (505 SB1, 505 SB2, and 505 NB1) and at nine sites in North Carolina (NC1, NC3, NC6, NC7, NC8, NC9, NC10, NC11, and NC12). Table I1 summarizes the maximum profile level and average speed information for all measured light vehicles. The lowest average maximum profile level was measured at slower speed Site NC8. The next two lowest average maximum profile levels were measured at 505 SB2 and NC9, both of which were among the lowest OBSI levels. The highest maximum profile level was measured at the uphill Site NC1, which had transverse tine PCC. On average, the maximum profile levels for the uphill sites were higher than the downhill and flat sites by less than 1 dBA and were higher than the Northern California sites and slower speed sites in North Carolina by 2.4 and 4.7 dBA, respectively. Table I1: Summary of maximum profile levels and vehicle speeds for light vehicles at all test sites Test Site Number of Vehicles Range of Maximum Profile Levels Average Maximum Profile Levels Average Vehicle Speed 505 SB1 2 87.1-88.0 dBA 87.5 dBA 70.5 mph 505 SB2 2 87.9-88.5 dBA 88.2 dBA 67.0 mph 505 NB1 9 85.9-92.6 dBA 89.3 dBA 70.5 mph NC1 9 90.0-95.9 dBA 93.2 dBA 71.4 mph NC3 7 87.3-95.2 dBA 90.0 dBA 67.0 mph NC6 13 87.1-96.2 dBA 91.3 dBA 66.4 mph NC7 9 87.0-93.9 dBA 89.6 dBA 65.7 mph NC8 12 83.4-91.9 dBA 86.0 dBA 40.8 mph NC9 13 82.1-94.6 dBA 88.9 dBA 66.3 mph NC10 7 88.1-94.3 dBA 91.0 dBA 71.7 mph NC11 8 86.4-92.4 dBA 89.5 dBA 68.8 mph NC12 10 87.2-93.0 dBA 90.1 dBA 65.2 mph Northern California Sites Figure I1 shows the light vehicle runs measured at the Northern California test sites. As shown in Table I1, the average maximum profile levels at each of the Northern California sites were 87.5 to 89.3 dBA, and as shown in the figures, profiles for typical light vehicles at these sites reduced by 10 dBA at heights ranging from 3.8 to 6.1ft (1.2 to 1.9m). Since light-duty vehicles are so much lower to the ground than heavy- and medium-duty vehicles, it is more difficult to distinguish between tire noise and other potential noise sources, such as the engine. The contours for a typical passenger vehicle (Run 56 at 505 SB1) are shown in Figure I2. Consistent with the profiles, the contours are low to the ground and centered about the pavement. The overall A- weighted contours are biased toward the front of the car, as are the contours for the 800 Hz band. At 1,250 Hz, the areas around the front and rear tires are more equal, indicating some contribution from the rear tire(s). The distribution bias in this case could be due to several reasons. The vehicle appears to be a typical front-wheel drive car, for which the loading on the front tires may be close to twice as much as it is for rear tires. From research done on the effect of tire loading on tire noise, the higher levels to the front could be due to higher loading of the
front tire the front tire noise Further, t relatively it cannot combinat Contours expected horizonta higher le contribut beyond t effect of Of the 13 from the noise at bands th louder th vehicle p Figure I1 normaliz s. Another p of the vehic may have he car is tra high, espec be determin ion of them for a typica , the contou l direction, vels tended ions from b he rear of th determining light-duty maximum p a height of at impacted an the quiet rofiles at 50 : Overall A ed to 94.1 dB lausible ex le. Since th a lesser im veling at 71 ially if this ed whether . l light vehi rs are clos relative to to be de oth the fron e car, whic the contour vehicles me rofile level 9.1ft (2.8m the overall est light-dut 5 NB1 were -weighted le A planation is is pavement portance th mph; so, th car has a fo either of th cle (Run 10 e to the pa the scaled p fined by th t and rear t h could ind s over a ±0. asured in N by 10 dBA ). This Toy results sho y vehicle pa quite simila vels for all I3 that powert was measu an on othe e engine R ur-cylinder ese explana 2) measured vement; ho hotograph e length of ires. In the icate exhau 1 sec interva orthern Cal at a heigh ota 4Runne wn in Figu ss-by. With r to those o light-duty v rain noise i red to be qu r surfaces r PM (and re engine. Fro tions is cor at 505 SB2 wever, they of the car. the car a 800 Hz ban st noise or l for a vehic ifornia, one t of 7.5ft (2 r had high re I1. This the excepti f 505 SB1 a ehicles meas s responsib ieter from t elative to p sultant engin m the avail rect or if it are shown stretched s For the 1,2 nd indicate d, the sourc could be du le traveling vehicle at 5 .3m) and h levels in th vehicle wa on of this ru nd 505 SB2 ured in Nor le for the bi he OBSI te owertrain n e noise) ma able informa is actually in Figure I omewhat in 50 Hz band d pass-by e region ex e to the blu at 69 mph. 05 NB1 red ad some tra e low frequ s less than n, the light . thern Calif as to sting, oise. y be tion, some 3. As the , the noise tends rring uced ce of ency 1 dB -duty ornia
Figure I2: Overall, 800, and 1,250 Hz con I4 tours of passenger car pass-by Run 56 at 505 SB1
Figure North Ca Uphill S Figure I4 vehicle ru the groun North Ca of domin Each ligh dBA at h I3: Overall, rolina Test ites. The av by red, blu ns show le d. This beh rolina, the b ant engine n t vehicle m eights rangi 800, and 1, Sites erage profi e, green, and vels within avior is show ehavior is m oise, possib easured at ng from 2.9 250 Hz cont les for uphi purple line 2ft (0.6m) o n at Sites 5 ore consiste ly from fron the uphill s to 6ft (0.9 t I5 ours of a lig ll Sites NC s, respectiv f the ground 05 SB2 and nt and more t-wheel driv ite reduced o 1.8m). At ht vehicle p 1, NC6, NC ely. At each that are gr 505 NB1, b exaggerate e vehicles. from the m noise levels ass-by Run 9, and NC of these sit eater than th ut at the fas d. This may aximum pr around 80 102 at 505 S 11 are show es, multiple e profile lev ter speed si be an indic ofile level b dBA, there w B2 n in light el at tes in ation y 10 as a
jump in s than thes to the he light veh at NC11 contours noise lev shown in up trucks Figure I4 North Ca Downhil Figure I5 sites typi light veh typical li the down between these ligh ource heigh e special ca avy and me icle runs are indicated s for these sp els in the lo the figures that are hig : Overall A rolina norm l Sites. Pro for Sites N cally reduce icles reduci ght vehicles hill sites an 7 and 8ft (2 t vehicles a ts at two lig ses, all nois dium truck consistentl ome noise a ecial cases, wer freque for these run her than wh -weighted l alized to 84 files for the C7 (red), NC d by 10 dB ng by 10 d have profil d the three .1 and 2.4m re pick-up tr ht vehicles a e sources fo profiles for y lower to th t heights be it was found ncy bands. s may indic at would be evels for al .5 dBA light vehic 10 (blue), a A at height BA at heigh es lower tha outliers at ), which is ucks or spo I6 long NC1 a r the light v these sites, e ground. T tween 8 to that each v While it ca ate a low fr common fo l light-duty les measur nd NC12 (g s ranging fr ts ranging n all heavy the uphill similar to t rt utility veh nd two light ehicles are the noise s he two veh 10ft (2.4 to ehicle was a nnot be con equency noi r other light vehicles me ed at the d reen). The om 3 to 5. from 6 to 6 and medium sites have l he medium icles (SUVs vehicles al below 7ft (2 ource heigh icles at NC1 3m). After pick-up tru firmed, the se source at vehicles. asured at t ownhill site light vehicle 5ft (0.9 to 1 .6ft (1.8 to trucks, the ow frequen truck profil ). ong NC11. O .1m). Comp ts for the ty and one ve a review o ck with elev profile beh heights for he uphill sit s are shown s at the dow .7m), with 2m). Whil three outli cy noise so es. In each ther ared pical hicle f the ated avior pick- es in the nhill three e the ers at urces case,
Figure I5 North Ca Level Si shown in there is o vehicle a typical li while at N typical li was a lar SUV, in : Overall A rolina norm tes. Seven Figure I6. bvious indi t NC3. Oth ght vehicle C3 these n ght vehicles ger SUV. T the region o -weighted le alized to 89 light vehicle Compared t cation of no er than the profiles at N oise reducti . The specia he contours f the bike ra vels for all .4 dBA s were me o Site NC1, ise sources two special C1 reduced ons occurre l case run a indicate the ck located o I7 light-duty v asured at N which had at two vehic cases at NC by 10 dBA d at heights t NC3 with presence o n the roof o ehicles meas C3, and the the same tra les at NC1 1 and the o at heights ranging from noise levels f an elevated f the vehicle ured at the profiles fo nsverse tine above 8ft ( ne special of 2.9 to 5.8 3.8 to 7ft at heights source nea . downhill si r these run PCC pavem 2.4m) and a case at NC3 ft (0.9 to 1 (1.2 to 2.1m above 8ft (2 r the back o tes in s are ent, t one , the .8m), ) for .4m) f the
Figure I6 North Ca Slower S collected runs show 2.2m). D at the gro other site : Overall A rolina norm peed Sites. was at Site a 10 dBA espite the sl und level, t s above. -weighted alized to 89 The only sl NC8. The reduction ower averag he profiles a levels for a .4 dBA ower speed 12 vehicles from the ma e vehicle sp t Site NC8 I8 ll light-duty site in Nort measured a ximum at h eeds measur are consiste vehicles m h Carolina t this site ar eights rang ed at this si nt with the easured at where light e shown in ing from 3. te and the lo typical prof the level sit vehicle data Figure I7. T 5 to 7.2ft (1 wer profile iles shown a es in was hese .1 to level t the
Figure I sites in N Test Site Figure I maximum curvature less cons site. For profiles w 7: Overall A orth Carolin Summary 8 shows the profile le s at heights istency than all but one ere within -weighted a normaliz average l vel of 89.5 within 2ft ( the heavy t site in No 5ft (1.5m) o levels for al ed to 89.5 dB ight vehicle dBA. The 0.6m) of the rucks. This rthern Cali f the ground I9 l light-duty A profiles at light vehi ground tha may have to fornia, nois and reduce vehicles m each site, cles show m n the mediu do with th e sources fo d by 10 dBA easured at normalized ore consis m truck ave e limited sam r the avera within 4.5 the slower s to the av tency in pr rage profile ple size at ge light ve ft (1.4m). peed erage ofile s but each hicle
Figure I8 BUS RE A total o NC6, NC and aver levels we level was site was dBA, res Table Test Site 505 SB2 NC6 NC7 NC14 NC16 : Average o SULTS f 11 buses w 7, NC14, an age speed i re measured measured a higher than pectively, an I2: Summa NumbeVehic 1 3 1 4 2 verall A-we ere measure d NC16 in nformation at slower t the uphill the downhil d was highe ry of maxim r of les Ran ighted levels d for this pr North Carol for all mea speed Sites Site NC6. O l site and N r than the s um profile l ge of Maxi Profile Lev -- 94.1-98.5 dB -- 77.7-88.1 dB 85.6-91.1 dB I10 for all ligh oject: 1 at 5 ina. Table I2 sured buses NC14 and N n average, t orthern Cali lower speed evels and ve mum els Av A A A t-duty vehic 05 SB2 in N summarize . The lowes C16, and t he maximum fornia site b sites in Nor hicle speeds erage Maxi Profile Lev 92.5 dBA 96.0 dBA 92.2 dBA 84.7 dBA 88.3 dBA les normaliz orthern Ca s the maxim t average m he highest m profile lev y approxim th Carolina for buses a mum els Av ed to 89.5 d lifornia and um profile aximum pr aximum pr els for the u ately 3.8 an by 9.5 dBA t all test site erage Vehic Speed 62.0 mph 59.0 mph 52.0 mph 40.0 mph 48.5 mph BA 10 at level ofile ofile phill d 3.5 . s le
The verti Table I2 level at h for heavy I10. The passed th axle tire attributab be influe there wa However dBA at a low frequ At the slo dBA gre behavior greater th this is a p Figure I9 and Nort cal distribut are shown eights rangi and medium maximum l rough the m s. From the le to the lar ncing the le s no indica , one bus ru height of 9 ency conten wer speed ater than th was observ an measure attern speci : Overall A h Carolina n ion of noise in Figure I9 ng from 4.6 trucks. Th evel was pro easurement 2,000 Hz ger rectangu ngth of the tion of ele n shown in ft (2.7m). A t in the 315 Sites NC14 e ground l ed by the o d for the oth fic to buses. -weighted l ormalized t levels for . Each run to 7.9ft (1.4 e contours f duced towa section. Th band, there lar exhaust contours fo vated noise Figure I9 t fter a review and 400 Hz and NC16, evel profile ther vehicle er vehicle ty evels for all o 90.6 dBA I11 all buses m reduced by to 2.4m), w or the bus m rd the end o e highest lev is an indi vent just be r the overa sources fo hat was tak of the con bands were there were b level at h types, exce pes. More t buses meas easured at a 10 dBA fr hich are on easured at f the pass-b els appear t cation that hind the re ll and the lo r the buse en at NC6 tours for thi influencing us profiles eights up to eding the g esting woul ured at the ll five test s om the max the lower 505 SB2 are y, as the re o be associa some of th ar tire. This wer freque s measured has overall s vehicle, it the overall that reached 4ft (1.2m round level d be require sites in Nor ites identifi imum at gr end of the ra shown in F ar half of th ted with the e noise ma source may ncies. Typic in this pr levels aroun was eviden noise result levels 0.5 t ). While si by 2.4 dBA d to determ thern Calif ed in ound nges igure e bus rear y be also ally, oject. d 75 t that s. o 2.4 milar was ine if ornia
Fig Test Site Figure I1 profile le dBA at h ure I10: Ov Summary 1 shows th vel of 90.7 eights rangi erall, 800, a e average b dBA. For a ng from 4.8 nd 2,000 Hz us profiles ll of the bu to 6.9ft (1.4 I12 contours of at each site ses shown i to 2.1m). a bus pass- , normalize n the figure by Run 120 d to the av , noise leve at 505 SB2 erage maxi ls reduced b mum y 10
Figure I11: Average overall A-weight I13 ed levels for all buses normalized to 90.7 dBA
