U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
| REPORT |
| This report is an archived publication and may contain dated technical, contact, and link information |
|
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| Publication Number: FHWA-HRT-16-036 Date: April 2016 |
Publication Number: FHWA-HRT-16-036 Date: April 2016 |
| Total Crashes | ||||||
|---|---|---|---|---|---|---|
| Negative binomial regression | Number of obs = | 297 | ||||
| Dispersion = mean | Wald chi2 (19) = | 287.53 | ||||
| Log pseudolikelihood = -717.62695 | Prob > chi2 = | 0.0000 | ||||
| TOT | | Coef. | Robust Std. Err. |
z | P > |z| | [95% Conf. | Interval] |
| Treated | | -.0425862 | .1101659 | -0.39 | 0.699 | -.2585075 | .1733351 |
| LNAADTMaj | | .4923199 | .1459936 | 3.37 | 0.001 | .2061778 | .7784621 |
| LNAADTMin | | .2154684 | .0385375 | 5.59 | 0.000 | .1399363 | .2910006 |
| Florida | | -.6362596 | .162479 | -3.92 | 0.000 | -.9547125 | -.3178067 |
| ThruLane5Up | | -1.065885 | .212755 | -5.01 | 0.000 | -1.482878 | -.6488932 |
| IntShoulder | | -.2946033 | .1243796 | -2.37 | 0.018 | -.5383828 | -.0508239 |
| ThruShoulder | | -.5656151 | .4716386 | -1.20 | 0.230 | -1.49001 | .3587795 |
| Thru5UpShlder | | 1.115338 | .5175464 | 2.16 | 0.031 | .1009653 | 2.12971 |
| FRTH_LEG | | -.2411121 | .1375897 | -1.75 | 0.080 | -.510783 | .0285588 |
| | | ||||||
| INT_SPEED | | ||||||
| 25 | | .2900747 | .354013 | 0.82 | 0.413 | -.4037781 | .9839275 |
| 30 | | .4594779 | .326298 | 1.41 | 0.159 | -.1800544 | 1.09901 |
| 35 | | .4942091 | .3434051 | 1.44 | 0.150 | -.1788526 | 1.167271 |
| 40 | | .3111814 | .3817203 | 0.82 | 0.415 | -.4369766 | 1.059339 |
| 45 | | .6799561 | .3540597 | 1.92 | 0.055 | -.0139882 | 1.3739 |
| 55 | | .4608651 | .3985745 | 1.16 | 0.248 | -.3203266 | 1.242057 |
| | | ||||||
| THRU_SPEED | | ||||||
| 40 | | -.1062967 | .3269923 | -0.33 | 0.745 | -.7471898 | .5345964 |
| 45 | | .2109157 | .2818383 | 0.75 | 0.454 | -.3414772 | .7633087 |
| 50 | | -.6465204 | .3619147 | -1.79 | 0.074 | -1.35586 | .0628194 |
| 55 | | .3262764 | .3029884 | 1.08 | 0.282 | -.26757 | .9201229 |
| _cons | | -4.541765 | 1.447841 | -3.14 | 0.002 | -7.379481 | -1.704048 |
| /lnalpha | | -1.429498 | .1727079 | -1.767999 | -1.090997 | ||
| alpha | | .239429 | .0413513 | .1706741 | .3358815 | ||
| Fatal and Injury Crashes | ||||||
|---|---|---|---|---|---|---|
| Negative binomial regression | Number of obs = | 297 | ||||
| Dispersion = mean | Wald chi2 (19) = | 56.78 | ||||
| Log pseudolikelihood = -491.09991 | Prob > chi2 = | 0.0000 | ||||
| TOT | | Coef. | Robust Std. Err. |
z | P > |z| | [95% Conf. | Interval] |
| Treated | | -.1669481 | .1334598 | -1.25 | 0.211 | -.4285246 | .0946283 |
| LNAADTMaj | | .3027534 | .1719295 | 1.76 | 0.078 | -.0342222 | .6397291 |
| LNAADTMin | | .1910633 | .0442966 | 4.31 | 0.000 | .1042436 | .277883 |
| Florida | | -.3316629 | .1961931 | -1.69 | 0.091 | -.7161943 | .0528685 |
| ThruLane5Up | | -.5849208 | .2753746 | -2.12 | 0.034 | -1.124645 | -.0451965 |
| IntShoulder | | -.232926 | .1670391 | -1.39 | 0.163 | -.5603168 | .0944647 |
| ThruShoulder | | -.7050994 | .5639856 | -1.25 | 0.211 | -1.810491 | .400292 |
| Thru5UpShlder | | .9365371 | .6267288 | 1.49 | 0.135 | -.2918288 | 2.164903 |
| FRTH_LEG | | -.2530672 | .1826752 | -1.39 | 0.166 | -.6111041 | .1049696 |
| | | ||||||
| INT_SPEED | | ||||||
| 25 | | .1490696 | .3936889 | 0.38 | 0.705 | -.6225465 | .9206857 |
| 30 | | .4573904 | .3566774 | 1.28 | 0.200 | -.2416845 | 1.156465 |
| 35 | | .2598806 | .3846343 | 0.68 | 0.499 | -.4939888 | 1.01375 |
| 40 | | .195327 | .4051539 | 0.48 | 0.630 | -.5987601 | .9894141 |
| 45 | | .3861851 | .3871922 | 1.00 | 0.319 | -.3726977 | 1.145068 |
| 55 | | .3522804 | .4505391 | 0.78 | 0.434 | -.53076 | 1.235321 |
| | | ||||||
| THRU_SPEED | | ||||||
| 40 | | .047759 | .3633107 | 0.13 | 0.895 | -.664317 | .759835 |
| 45 | | .1691577 | .3103545 | 0.55 | 0.586 | -.439126 | .7774414 |
| 50 | | -.2235057 | .4191268 | -0.53 | 0.594 | -1.044979 | .5979676 |
| 55 | | .3347177 | .3418134 | 0.98 | 0.327 | -.3352244 | 1.00466 |
| _cons | | -3.635727 | 1.696434 | -2.14 | 0.032 | -6.960676 | -.3107779 |
| /lnalpha | | -2.569357 | .5916134 | -3.728898 | -1.409816 | ||
| alpha | | .0765848 | .0453086 | .0240193 | .2441883 | ||
| Target Crashes | ||||||
|---|---|---|---|---|---|---|
| Negative binomial regression | Number of obs = | 297 | ||||
| Dispersion = mean | Wald chi2 (19) = | 324.75 | ||||
| Log pseudolikelihood = -599.30626 | Prob > chi2 = | 0.0000 | ||||
| TOT | | Coef. | Robust Std. Err. |
z | P > |z| | [95% Conf. | Interval] |
| Treated | | -.0835338 | .1294228 | -0.65 | 0.519 | -.3371979 | .1701303 |
| LNAADTMaj | | .562835 | .1689981 | 3.33 | 0.001 | .2316047 | .8940652 |
| LNAADTMin | | .2251839 | .0441408 | 5.10 | 0.000 | .1386696 | .3116982 |
| Florida | | -1.173519 | .2142147 | -5.48 | 0.000 | -1.593372 | -.7536656 |
| ThruLane5Up | | -1.448441 | .3416042 | -4.24 | 0.000 | -2.117973 | -.7789092 |
| IntShoulder | | -.5076138 | .1700634 | -2.98 | 0.003 | -.840932 | -.1742957 |
| ThruShoulder | | -1.920895 | .7262517 | -2.64 | 0.008 | -3.344322 | -.4974676 |
| Thru5UpShlder | | 2.536511 | .7922779 | 3.20 | 0.001 | .9836746 | 4.089347 |
| FRTH_LEG | | -.273681 | .1758453 | -1.56 | 0.120 | -.6183315 | .0709695 |
| | | ||||||
| INT_SPEED | | ||||||
| 25 | | .256837 | .5060215 | 0.51 | 0.612 | -.734947 | 1.248621 |
| 30 | | .6727153 | .4797619 | 1.40 | 0.161 | -.2676008 | 1.613031 |
| 35 | | .6383726 | .5020733 | 1.27 | 0.204 | -.3456729 | 1.622418 |
| 40 | | .1977973 | .5548589 | 0.36 | 0.721 | -.8897061 | 1.285301 |
| 45 | | .9045994 | .5159448 | 1.75 | 0.080 | -.1066339 | 1.915833 |
| 55 | | .4433076 | .5625622 | 0.79 | 0.431 | -.659294 | 1.545909 |
| | | ||||||
| THRU_SPEED | | ||||||
| 40 | | -.4655281 | .4043569 | -1.15 | 0.250 | -1.258053 | .3269969 |
| 45 | | -.0891576 | .3453978 | -0.26 | 0.796 | -.7661249 | .5878096 |
| 50 | | -1.248241 | .4890602 | -2.55 | 0.011 | -2.206782 | -.2897009 |
| 55 | | -.1768242 | .3604577 | -0.49 | 0.624 | -.8833083 | .5296598 |
| _cons | | -4.831303 | 1.644516 | -2.94 | 0.003 | -8.054495 | -1.60811 |
| /lnalpha | | -1.257409 | .2205592 | -1.689697 | -.8251205 | ||
| alpha | | .2843901 | .0627248 | .1845755 | .4381822 | ||
| Total Crashes | ||||||
|---|---|---|---|---|---|---|
| Mixed-effects nbinomial regression | Number of obs = | 434 | ||||
| Overdispersion: mean | ||||||
| Group variable: Location | Number of groups = | 73 | ||||
| Wald chi2 (11) = | 76.07 | |||||
| Log likelihood = -938.44718 | Prob > chi2 = | 0.0000 | ||||
| TOT | | Coef. | Std. Err. | z | P>|z| | [95% Conf. | Interval] |
| Treated | | -.0464587 | .160353 | -0.29 | 0.772 | -.3607448 | .2678274 |
| LNAADTMaj | | .5911802 | .2070058 | 2.86 | 0.004 | .1854563 | .9969041 |
| LNAADTMin | | .1827335 | .0580069 | 3.15 | 0.002 | .0690421 | .2964249 |
| | | ||||||
| THRU_SPEED | | ||||||
| 40 | | .1020133 | .322451 | 0.32 | 0.752 | -.5299791 | .7340057 |
| 45 | | .3045244 | .2456019 | 1.24 | 0.215 | -.1768465 | .7858953 |
| 50 | | -.2461067 | .3788936 | -0.65 | 0.516 | -.9887245 | .4965112 |
| 55 | | .7239126 | .3226377 | 2.24 | 0.025 | .0915543 | 1.356271 |
| 60 | | -.3522544 | .6128105 | -0.57 | 0.565 | -1.553341 | .8488322 |
| | | ||||||
| ThruLane5Up | | -.6136113 | .3164582 | -1.94 | 0.053 | -1.233858 | .0066354 |
| DEFLECTION | | .008991 | .0058116 | 1.55 | 0.122 | -.0023995 | .0203816 |
| Florida | | -.7244923 | .1486832 | -4.87 | 0.000 | -1.015906 | -.4330787 |
| _cons | | -5.541216 | 1.969354 | -2.81 | 0.005 | -9.401079 | -1.681353 |
| /lnalpha | | -3.567961 | .4746443 | -7.52 | 0.000 | -4.498246 | -2.637675 |
| Location | | ||||||
| var(_cons) | | .2120851 | .0475991 | .1366066 | .3292674 | ||
| LR test vs. nbinomial regression:chibar2(01) = 133.20 Prob> = chibar2 = 0.0000 | ||||||
| Fatal + Injury Crashes | ||||||
|---|---|---|---|---|---|---|
| Mixed-effects Poisson regression | Number of obs = | 434 | ||||
| Group variable: Location | Number of groups = | 73 | ||||
| Wald chi2 (11) = | 33.52 | |||||
| Log likelihood = -665.20078 | Prob > chi2 = | 0.0004 | ||||
| FI | | Coef. | Std. Err. | z | P>|z| | [95% Conf. | Interval] |
| Treated | | -.1341782 | .1386713 | -0.97 | 0.333 | -.405969 | .1376126 |
| LNAADTMaj | | .4430583 | .1845915 | 2.40 | 0.016 | .0812656 | .8048511 |
| LNAADTMin | | .1164183 | .0520172 | 2.24 | 0.025 | .0144663 | .2183702 |
| | | ||||||
| THRU_SPEED | | ||||||
| 40 | | .4292983 | .2915357 | 1.47 | 0.141 | -.1421011 | 1.000698 |
| 45 | | .4049865 | .2221222 | 1.82 | 0.068 | -.0303651 | .840338 |
| 50 | | .1067951 | .3398837 | 0.31 | 0.753 | -.5593647 | .772955 |
| 55 | | .880773 | .2837816 | 3.10 | 0.002 | .3245713 | 1.436975 |
| 60 | | -.6526719 | .6898198 | -0.95 | 0.344 | -2.004694 | .6993501 |
| | | ||||||
| ThruLane5Up | | -.5191403 | .2780189 | -1.87 | 0.062 | -1.064047 | .0257668 |
| DEFLECTION | | .0038474 | .0051373 | 0.75 | 0.454 | -.0062215 | .0139162 |
| Florida | | -.1913353 | .1319369 | -1.45 | 0.147 | -.4499269 | .0672564 |
| _cons | | -4.805059 | 1.750959 | -2.74 | 0.006 | -8.236877 | -1.373242 |
| Location | | ||||||
| var(_cons) | | .1022855 | .0363784 | .0509425 | .2053754 | ||
LR test vs. nbinomial regression: chibar2(01) = 24.23 Prob> = chibar2 = 0.0000 |
||||||
| Target Crashes | ||||||
|---|---|---|---|---|---|---|
| Mixed-effects nbinomial regression | Number of obs = | 433 | ||||
| Overdispersion: mean | ||||||
| Group variable: Location | Number of groups = | 73 | ||||
| Wald chi2 (11) = | 91.98 | |||||
| Log likelihood = -805.26016 | Prob > chi2 = | 0.0000 | ||||
| Target | | Coef. | Std. Err. | z | P>|z| | [95% Conf. | Interval] |
| Treated | | -.0337268 | .1915727 | -0.18 | 0.860 | -.4092025 | .3417488 |
| LNAADTMaj | | .5266724 | .2497115 | 2.11 | 0.035 | .0372468 | 1.016098 |
| LNAADTMin | | .1948996 | .0712121 | 2.74 | 0.006 | .0553264 | .3344728 |
| | | ||||||
| THRU_SPEED | | ||||||
| 40 | | -.0171329 | .398288 | -0.04 | 0.966 | -.7977631 | .7634973 |
| 45 | | .3838796 | .3013736 | 1.27 | 0.203 | -.2068017 | .974561 |
| 50 | | -.1985112 | .4589208 | -0.43 | 0.665 | -1.097979 | .700957 |
| 55 | | .6631016 | .393477 | 1.69 | 0.092 | -.108099 | 1.434302 |
| 60 | | -.4246656 | .7859793 | -0.54 | 0.589 | -1.965157 | 1.115826 |
| | | ||||||
| ThruLane5Up | | -.8200212 | .3790982 | -2.16 | 0.031 | -1.56304 | -.0770024 |
| DEFLECTION | | .0100721 | .0069324 | 1.45 | 0.146 | -.0035152 | .0236594 |
| Florida | | -1.158089 | .1774422 | -6.53 | 0.000 | -1.505869 | -.8103083 |
| _cons | | -5.133955 | 2.36076 | -2.17 | 0.030 | -9.76096 | -.5069502 |
| /lnalpha | | -3.240642 | .5155851 | -6.29 | 0.000 | -4.251171 | -2.230114 |
| Location | | ||||||
| var(_cons) | | .2840945 | .0674521 | .1783871 | .4524413 | ||
LR test vs. nbinomial regression: chibar2 (01) = 108.78 Prob> = chibar2 = 0.0000 |
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