1 00:00:00,072 --> 00:00:05,072 (dramatic music) (logo whooshing) 2 00:00:09,600 --> 00:00:10,433 - [Narrator] Weather conditions 3 00:00:10,433 --> 00:00:12,690 around Texas make roadway maintenance 4 00:00:12,690 --> 00:00:14,730 a locally unique endeavor. 5 00:00:14,730 --> 00:00:17,940 In North Texas, for example, snowplows are necessary 6 00:00:17,940 --> 00:00:20,370 for clearing the roads during winter. 7 00:00:20,370 --> 00:00:21,840 That often results in ripping up 8 00:00:21,840 --> 00:00:25,590 retroreflective pavement markers, or RPMs, 9 00:00:25,590 --> 00:00:27,900 which are raised safety devices on the roadway 10 00:00:27,900 --> 00:00:30,540 that helps drivers navigate hazards. 11 00:00:30,540 --> 00:00:32,760 Building on a previous research project, 12 00:00:32,760 --> 00:00:35,070 the Texas Department of Transportation determine how 13 00:00:35,070 --> 00:00:38,223 to protect RPMs within the current infrastructure. 14 00:00:39,120 --> 00:00:43,072 - My whole point of this is that every winter we plow off 15 00:00:43,072 --> 00:00:46,920 millions of dollars worth of RPMs 16 00:00:46,920 --> 00:00:49,560 while we're plowing snow off of our highways. 17 00:00:49,560 --> 00:00:54,210 The RPMs come off with the snow 18 00:00:54,210 --> 00:00:55,890 through this process, and so we have 19 00:00:55,890 --> 00:00:58,140 to replace 'em every year. 20 00:00:58,140 --> 00:01:01,830 So the thought is if we put these RPMs 21 00:01:01,830 --> 00:01:04,140 and recess 'em in these already 22 00:01:04,140 --> 00:01:07,380 existing milled rumble strips, that 23 00:01:08,640 --> 00:01:09,630 that when we come back 24 00:01:09,630 --> 00:01:11,730 through the plow, we won't plow 'em off. 25 00:01:11,730 --> 00:01:14,460 - And one of the major things is that we wanted to make sure 26 00:01:14,460 --> 00:01:16,560 that people can actually see 27 00:01:16,560 --> 00:01:19,080 the retroflective pavement markers while 28 00:01:19,080 --> 00:01:20,850 installed in the rumble strips. 29 00:01:20,850 --> 00:01:23,850 For the previous project, we did it with a small team. 30 00:01:23,850 --> 00:01:27,240 For this project, we actually did human nighttime visibility 31 00:01:27,240 --> 00:01:30,274 studies in which we recruited participants to 32 00:01:30,274 --> 00:01:34,072 participate in the project to determine 33 00:01:34,072 --> 00:01:36,364 whether they can actually see it. 34 00:01:36,364 --> 00:01:40,440 - [Glenn] This particular project, it really went in 35 00:01:40,440 --> 00:01:45,440 and looked at that reflectivity values to make sure 36 00:01:45,916 --> 00:01:48,210 that it was still meeting our standards, even though 37 00:01:48,210 --> 00:01:50,640 that they were recessed into the pavement. 38 00:01:50,640 --> 00:01:52,230 - [Raissa] Our results essentially showed 39 00:01:52,230 --> 00:01:55,140 that the markers had a really high survival rates when they 40 00:01:55,140 --> 00:01:57,600 were installed in that approach compared 41 00:01:57,600 --> 00:01:59,730 to surface mounting markers. 42 00:01:59,730 --> 00:02:02,130 In addition, based off of some work that we did on 43 00:02:02,130 --> 00:02:05,610 that project, we found that the visibility 44 00:02:05,610 --> 00:02:07,980 was approximately around 900 feet. 45 00:02:07,980 --> 00:02:09,677 - During the winter, 46 00:02:09,677 --> 00:02:12,630 we would plow these reflective pavement markers off the road 47 00:02:12,630 --> 00:02:14,340 and while we would come back 48 00:02:14,340 --> 00:02:16,830 and install 'em at a later date, there was a number 49 00:02:16,830 --> 00:02:19,140 of months where those markers were 50 00:02:19,140 --> 00:02:21,450 non-existent on our highways. 51 00:02:21,450 --> 00:02:26,450 And so by putting 'em in these milled rumble strips 52 00:02:26,846 --> 00:02:29,190 and recessing 'em where they're not plowed off, 53 00:02:29,190 --> 00:02:31,290 they're on the highway all the time. 54 00:02:31,290 --> 00:02:34,050 - And when we think about how much money is going 55 00:02:34,050 --> 00:02:38,107 to be saved, we estimated around $3.5 million a year 56 00:02:38,107 --> 00:02:42,540 just based off of having these RPMs in the pavement. 57 00:02:42,540 --> 00:02:45,030 And I would say that's a conservative estimate 58 00:02:45,030 --> 00:02:48,120 because we estimated around 75% of them are going 59 00:02:48,120 --> 00:02:50,730 to persist, and it's likely that that could be higher. 60 00:02:50,730 --> 00:02:53,970 One of the key findings is that the rumble strips need 61 00:02:53,970 --> 00:02:55,800 to be at a certain depth. 62 00:02:55,800 --> 00:02:57,810 So we're looking at developing approach, 63 00:02:57,810 --> 00:03:00,930 perhaps using lasers in which we can quickly scan 64 00:03:00,930 --> 00:03:03,930 existing rumble strips to determine whether they're at the 65 00:03:03,930 --> 00:03:07,950 appropriate depths, so that way this method can be deployed. 66 00:03:07,950 --> 00:03:12,210 In terms of future highways in which you are now cutting in 67 00:03:12,210 --> 00:03:16,560 new rumble strips, the major next steps will be to make sure 68 00:03:16,560 --> 00:03:19,890 that contractors can cut these rumble strips 69 00:03:19,890 --> 00:03:22,380 at the appropriate depths and tolerances. 70 00:03:22,380 --> 00:03:25,863 So we are creating recommendations for contractors. 71 00:03:27,060 --> 00:03:28,260 - [Narrator] For more information 72 00:03:28,260 --> 00:03:30,660 and to find the publication for this project, 73 00:03:30,660 --> 00:03:33,000 please visit the Tex DOT research library 74 00:03:33,000 --> 00:03:34,200 at the link shown below.