D. She pard Frank Engineer Research opinions, findings, and conclusions expressed ( are those of author and not necessarily report Highway & Transportation Research Virginia Organization Sponsored Jointly by Cooperative 197 9 March 79-R38 VHTRC Council Virginia REPORT FINAL FOR CONSTRUCTION A HIGHWAY ADVISORY RADIO AND MAINTENANCE OPERATIONS by in this those of sponsoring agencies.) (A and of Highways & Transportation Department University of Virginia) Charlottesville, Virginia
TRAFFIC RESEARCH ADVISORY COMMITTEE MR. D. B. HOPE, Chairman, District Engineer, VDHST MR. R. G. CORDER, Transp. Coordination Engineer, VDH&T MR. L. H. DAWSON, JR., Asst. Traffic & Safety Engineer, VDH&T MR. J. E. GALLOWAY, JR., Asst. Materials Engineer, VDHST DR. JAMIE HURLEY/ Assistant Professor of Civil Engineering, VPI $ SU MR. C. 0. LEIGH, Maintenance Engineer, VDHgT MR. R. F. MCCARTY, Safety Coordinator, FHWA MR. J. P. MILLS, JR., Traffic & Safety Engineer, VDH&T MR. W. C. NELSON, JR. Asst. Traffic $ Safety Engineer, VDHST MR. R. L. PERRY, Asst. Transportation Planning Engineer, VDHgT MR. B. C. PIERCE, District Traffic Engineer, VDH&T MR. R. N. ROBERTSON, Research Engineer, VHgTRC MR. F. D. SHEPARD, Research Engineer, VH&TRC ±i
Virginia Department of Highways and Transportation an advisory radio to advise motorists of possible de- utilized caused by resurfacing operations on a major interstate lays and to give information concerning use of an avail- highway detour. This report describes an evaluation of effec- able of radio unit on basis of use made of tiveness messages by motorists and effect of messages on radio flow through maintenance area and available detour. traffic of inability of motorists to tune in frequency or cause hear or understand message; however, it is felt that to of highway advisory radio has good potential as a concept of information and possible aid to motorists. source SUMMARY results of traffic counts, time delay runs, and a motorist indicated that unit used was not fully effective be- survey iii
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HIGHWAY ADVISORY RADIO FOR CONSTRUCTION A MAINTENANCE OPERATIONS AND D. Shepard Frank Engineer Research and construction operations, in combination Maintenance increasing traffic volumes on interstate highways, with cause congestion resulting in traffic backups and delays. often view of extensive maintenance and construction work In for interstate and primary highways in Virginia, scheduled Department of Highways and Transportation purchased a highway radio unit to help alleviate anticipated traffic con- advisory Because of uniqueness of this unit and Depart- gestion. purpose of study was to evaluate highway advisory unit on basis of its use and effect of broad- radio messages on flow of traffic through a pavement resur- casted project on 1-95 near Fredericksburg. unit was used to facing motorists of possible delays caused by maintenance advise and to provide information on an alternate route (Rte. I) operations study was limited to an evaluation of effectiveness of radio advisory system for purposes and particular circum- radio apparatus consists of an audio sine, Ii0 milliwatt Model Number AM!00-11S, and a recorder tape player, transmitter, 237. FINAL REPORT by INTRODUCTION lack of experience in using it, Research Council was ment's to assist in evaluating it. asked PURPOSE AND SCOPE that could be used as a detour to.avoid delay. stances cited. HIGHWAY ADVISORY RADI0 Hardware
number AL 187 R. 8-ft. antenna for unit was mounted model above ground adjacent to interstate and prior to 30-ft. of highway being resurfaced. approximate transmitting section for this particular setup was a 1/2 mi. radius for one-third range volume. message was carried on a 30-sec. continuous radio tape with 28 sec. of recording and 2 sec. of silence. cassette and Application Ins_tal.!at$on.. noted above, unit was used to advise motorists of possi- As delays caused by resurfacing operations on 1-95 and offered ble concerning use of an available detour. message information are tuned to Virginia highway advisory You northbound lanes of Interstate 95 radio. being resurfaced for next i0 miles for are comfort and safety. 0nly one lane of your is now moving through work area. traffic may wish to leave interstate at You interchange and follow Route 1 to Route 630 next Stafford, where you can return to Interstate at for travel to north. Watch for signs and 95 carefully. drive map of area encompassing advisory radio, work A and Rte. 1 detour is shown in Figure i. section of area, 1 used as a detour passes through Fredericksburg and is a 4- Rte. primary highway (1.5 mi. divided) 14 mi. long. Speed limits lane section vary from 35-45 mph in Fredericksburg urban area on 4 mi.) to 55 mph in or areas. re are eight (approximately signals along detour with majority being in traffic of Fredericksburg. distance on 1-95 between Rte. 1 vicinity advisory radio was positioned adjacent to 1-95 approxi- 3/4 mi. from Rte. 1 exit as shown in Figure 2. Three mately of signs provided information concerning activity ahead sets possible avoidance of' delay by tuning radio to AM 1200 and following advisory instructions. Signs were set 300 ft. and within each set. advisory message could be picked up apart passing second set of signs and lasted until vehicle after approximately 1/4 mile from Rte. 1 detour. was was as follows: and Rte. 630 is 14.5 mi. adjacent to advisory radio is a 4-lane divided high- 1-95 with an average daily traffic volume of 3,000 vehicles. way
Figure I. Map of area encompassing advisory radio. Return to 1-95 Detour Route Fredericksburg, Virginia i Detour Radio Highway Advisory
237 0.M 0.,--I 0 o 0 0.,-t 0 e,,o 1. H 0 0 " O
an evaluation of highway radio advisory in use For above, data were accumulated for 5 days; days with explained radio on (7/28/78, 7/27/78, and 8/8/78) and 2 days with it (7/25/78 and 8/2/78). Data were taken between hours of off a.m. and 7.00 p.m.. location of resurfacing operation 9"00 from day to day, but no part of it was visible to north- varied volume counts weme made at intersection of 1-95 Tmaffic and Rte. 1 (Massaponax intemchange) to determine in- northbound in traffic on Rte. l, mesulting from advisory madio. crease included volumes on 1-95 and Rte.! off-mamp fore Counts.Runs, Time-Delay muns were made for traffic memaining on 1-95 and Time-delay following suggested Rte. 1 de,our. se data were traffic so That travel Times for routes could be compared. gamed vehicles weme used in determining time required for travel Two Rte. 1 exit and Rte. 6 0-Staffomd interchange. between of vehicles were told to flow with traffic and to altem- drivers moutes. Also, y weme instructed to note milepost of nate start of any traffic backup, location of work area, and or impediment to flow of Traffic. any interviews were conducted at Dumfries rest area Motorist approximately 30 mi. north of work area on 1-95 to located percentage of northbound traffic exiting at Rte. I is shown in Table i. As noted 1.8% and 1.6% more traffic interchange 2377 PROCEDURE bound motorist prior to his reaching Rte. l.exit. Tmaffic Counts days with advisomy radio on and 2 days with it off. Motorist Interview information concerning motorists' use of advisory radio gar and ir choice of routes. system RESULTS Traffic Counts
on Tuesday and Wednesday, respectively, when advisory exited was in operation. Volumes were recorded for same time radio Percentages of Traffic Exiting Rte. I 2 gives average travel times for alternate routes Table with average backup on 1-95. travel time on 1-95 is along function of length of backup on this route, with a travel times generally corresponding with longer backups. higher in most cases travel times were higher for 1-95 than for Rte. Also, With available data, it is difficult to say with any cer- I. what influence advisory radio had on relative travel tainty because of influence of variables such as traffic vol mne, times of work area, interchange location, accidents, and wear. location example, on Wednesday, July 26, 1978, work area was prior For Rte. 17 interchange and re was little or no backup and to low travel times. For all or days, work area relatively past Rte. 17 and re was increased congestion as a result of was entering 1-95 from Rte. 17. traffic Travel Times for 1-95 and Reute I intervals for 7½ hr. on Tuesdays and for 5 hr. on Wednesdays. Table 1 Tuesday Wednesday 7/25 Unit Off 8/8 Unit On 8 2 Unit Off 7/26 Unit On 15.5% 17.3% 13.9% 15.5% Table 2 Advisory Average Number, 1-95 Comparative Day Try_re i of Average Volumes Radio Runs Backup Time, mi rain 1-95 Rte. I 1-95 Rte.! I-g5 Rte. i Tue. 7/25 OFT 37.4 22.8 9 8 2.8 8633 1212 Tue. 8/8 ON 30.3 24.7 8 8 2.6 6905 1446 Wed. 812 OFF 23.7 22.2 S 4 I. 7 5470 80i Wed. 7 / 26 ON 15.1 23.7 8 8 0.0 5156 970 Thur. 7 27 ON 33.2 26.7 5 7 3.2
were obtained from 849 motorists for 3 days Interviews 7/27/78 and 8/8/78) while radio advisory was in (7/26/78, includes --percentages of motorists' responses for which Following this figure are comments on responses questions. questionnaire survey is being conducted by Virginia This of Highways and Transportation for purpose of im- Department safety and convenience of motorist traveling proving areas in which construc ion and maintenance ac through raking place. Your cooperation in answering some questions are be appreciated. Thank you. will Did you notice signs about 30 miles back referring to i. of your car's A rzdio for highway information? use Under Construction Next i0 Milts) (Road May Avoid De lay) (You 90.5% yes no (if no, ask origin and destination and terminate g.5 interview) f you have a radio, did you tune ro 1200 and hear advisory 3. message? 56.1 no 53.9 o Figure 3. Questionnaire responses. 2379 Motomist Interview y were asked questions relating to highway operation. radio using questionnaire shown in Figure 3, advisory to each question asked. (Tune Radio, "I 1200 Hertz Cycles) 2. r hich of following do you have in your vehicle? 77.4 radio 1.2 CB 3.2 neir (18.2 both) 3.9 yes Did you understand message? 3. I yes Which of fio].low±ng outes did you ta e? i stayed on Interstate 95 89: 7 [ took Route 1 detour!0.3 what did you base your decision as to which route o take? Or;, Radio advisory aessage 7.9 9 7 B 2.4 Or (please explain) 7. hat is your origin and destination 8. Comments
Did you notice advisory signs about 30 mi. back referring i. use of your car's AM radio for highway information? to was interesting to note that almost 10% of It had not seen signs although re were three motorists of signs with each sign having double indications. sets were no comments on questionnaires indicating re was expected, a large percentage (96 ) had AM radios; As had both CB and AM radios. One percent had CB radios only; 18 If you have a radio, did you tune to 1200 AM and hear 3. message? advisory percent of motorists had tuned to 1200 AM Forty-four heard message; 56% had not. Based on comments, and of motorists had tried to find message, however, many could not. and 44% who had tuned to 1200 AM and heard message, Of 36% had understood it. Many reasons for not having.been only to understand message were noted in comments; how- able most prevalent were that " entire message was not ever, or " message was not clear", se findings indicate heard" 16% of motorists on 1-95 had tried to pick up that percent had taken 1-95 while or 10% had Ninety Rte. I. Some of motorists who had taken Rte. 1 traveled that y had done so for reasons or than indicated advisory. radio was found that decision on which route to take had It based on advisory radio 8% of time; however, 31% been those having based ir decision on advisory radio had of on interstate. CB radio had been responsible for stayed motorists' decision 10% of time and 72% of se re- had stayed on interstate. spondents that signs were ineffective. 2. Which of following do you have in your vehicle? 3 had neir. 4. Did you understand message? message and had been able to understand.it. 5. Which of following routes did you take? 6. On what did you base your decision as to which route to take?
question was asked to determine if motorist This traversed area containing highway radio advisory had majority of questionnaires did not have comments; those comments from motorists who had stayed on 1-95 however, fastest, best, simplest, or most Shortest, route. direct moving or no backup. Traffic no hurry. In not hear message. Could not clear or poor reception. Message CB radio was monitored during 5-day (3 days on and 2 A off) period for which data were taken. re was frequent days on CB radio concerning resurfacing work, traffic talk on 1-95, and directions concerning Rte. 1 detour, even backup conditions. Also, because of many variables associated with of overall operation, conclusions are in general terms. Furr, is realized that a degree of bias may be expected since inter- it was limited to a rest area; however, it was felt that viewing on evaluation, use of highway advisory radio Based advise motorists was not fully effective because of inability to 7. What are your origin and destination? message. 8. Comments. are loosely categomized below. Followed tmaffic. Could not locate station. CB Usage when advisory radio was off. CONCLUSIONS AND RECOMMENDATIONS should be reiterated that advisory radio was evaluated It only one project and that results thus reflect only one set on results were useful for purposes of this study.
most motorists to tune in frequency or to hear or under- of message. Although only 16% of motorists actually stand it in. This effort on part of motorists indicates tune concept of highway radio advisory has good potential that a source of information and possible aid to motorists. Also, as is felt that, regardless of wher specific instructions are it or followed, advisory radio informs motorists of given conditions and is an asset in public relations. Based on road unfamiliar with detour route and re is no visual evidence is a traffic backup. of note should be made of comments received from Special concerning maintenance operations. re were generally public complaints received when advisory radio was used as com- fewer with those received without advisory radio. This would pared to support use of a highway radio advisory as a source of tend adding to public acceptance of traffic conges- information future evaluations of this type, it is recommended that a For powerful radio advisory system be used. Although not directly more to this evaluation, following suggestions may be con- related for future use of highway advisory radio. sidered Messages or tapes might be changed to correspond 2. changing conditions. to "One or more units might be used in conjunction 3. each or. with A special CB channel might be used to obtain in- 5. on motorists' reactions. formation Special emergency broadcasts with radio 6. might be feasible. advisory 2382 and understood message, it is important to note that received half motorists having radios in ir vehicles tried to over to questionnaire, it seems that if motorist is responses a choice, he is reluctant to use a detour, especially if he given tion resulting from maintenance and construction operations. message should be as short and simple i. possible. as A mobile unit with live voice communication might 40 effective. be I0