ERRATA. Recently, we were made aware of some technical revisions that need to be applied to the Highway Safety Manual Supplement.

Transcription

1 ERRATA March 2016 Dear Custoer: Recently, we were ade aware of soe technical revisions that need to be applied to the Highway Safety Manual Suppleent. Changes are reflected by color-coded highlights on individual pages throughout errata file changes are highlighted in green. Please scroll down to see the full erratu. In the event that you need to download this erratu file again, please download fro: In order to see color-coding on a hard copy printout, please select Docuent and Markups in the Print dialog box when selecting your print options so that highlighting will be displayed properly. Then, please replace the existing pages with the corrected pages to ensure that your edition is both accurate and current. AASHTO staff sincerely apologizes for any inconvenience. HSM-1-E3-

2 Errata to the Highway Safety Manual, 1 st Edition and Suppleent 2016 errata changes in green (bold) Page Existing Text Corrected Text Suppleent In Eq : CMF8, fs, ac, sv, z 1.0 Pc, i fc, i i 1 exp a[ Ws 10] Pc, i fc, i i 1 exp b[ W 10] s Make the following change to the equation: CMF8, fs, ac, sv, z 1.0 Pc, i i 1 exp a[ Ws 10] Pc, i i 1 exp b[ W 10] s In Eq : CMF9, fs, ac, sv, fi 1.0 Pc, i fc, i i 1 ftan Pci, fci, 1.0 i 1 Make the following change to the equation: CMF9, fs, ac, sv, fi 1.0 Pc, i i 1 ftan Pci, 1.0 i In the first paragraph, last sentence; and the third paragraph, last sentence: is less than 0.75 ft, then it should Make the following text change: is less than 0.75 ft, then Wicb should Following Table Please add the following text: The curve entry speeds need to be calculated for all curves fro ilepost 0.0 to the end of the analysis segent. This ay include segents of an adjacent rap that are not included in the current analysis segent. For each curve, record the entry speed, the total length of the curve, and the length of the current analysis segent. Once the procedure on the following pages is copleted, return to Equation In this equation, the suation ter only includes entry speeds and radii that have a length in the current analysis segent. other curves analyzed should be ignored if they are not part of the current analysis segent. HSM-1S-E1 1 March 2016

3 2016 Errata Changes to the Highway Safety Manual, 1st Edition HIGHWAY SAFETY MANUA SUPPEMENT Table Cross Section (x) Crash Type (y) Crash Severity (z) a b c d Any cross section Multiple ) CMF 7, fs, ac, v, fi (ac) vehicle (v) Property daage only (pdo) CMF 7, fs, ac, v, pdo If the segent is in a Type B weaving section, then the length of the weaving section is an input to the CMF. The variables for weaving section length (i.e., wev, inc, wev, dec ) in Equation and Equation are intended to re- two equations indicates that the lane change CMF value will increase if the segent is in a Type B weaving section. The aount of this increase is inversely related to the length of the weaving section. Guidance for deterining if a weaving section is Type B is provided in Section The variables P wevb, inc and P wevb, dec in Equation and Equation 18-32, respectively, are coputed as the ratio of the length of the weaving section in the segent to the length of the freeway segent fs. If the segent is wholly located in the weaving section, then this variable is equal to 1.0. The X and AADT Two of the raps of interest are on the side of the freeway with travel in the increasing ilepost direction. One rap on this side of the freeway is upstrea of the segent, and one rap is downstrea of the segent. Siilarly, one rap on the other side of the freeway is upstrea of the segent and one rap is downstrea. Only those entrance interest. For siilar reasons, an upstrea exit rap is not of interest. The lane change CMF is applicable to any segent in the vicinity of one or ore raps. It is equally applicable to segents in a weaving section (regardless of the weaving section type) and segents in a non-weaving section (i.e., segents between an entrance rap and an exit rap where both raps have a speed-change lane). If the weaving plicable to weaving section lengths between 0.10 and 0.85 i. It is applicable to any value for the distance variable X and to the range of rap AADTs in Table The two SPFs for predicting speed-change-related crash frequency (i.e., Equation and Equation 18-22) are not used when evaluating a weaving section because the raps that for the weaving section do not have a speedchange lane. As a result, the predicted crash frequency for the set of segents that coprise a weaving section will tend to be saller than that predicted for a siilar set of segents located in a non-weaving section but having entrance and exit raps. This generalization will always be true for weaving sections that are not Type B. It ay or ay not hold for the Type B weaving section, depending on the length of the weaving section. CMF fs, ac, sv, z Two CMFs are used to describe the relationship between average outside shoulder width and predicted crash fre- fs, n, sv, ); and fs, n, sv, pdo). The base condition is a 10-ft outside shoulder width. The CMFs are described using the following equation: (18-35) 2014 by the Aerican Association of State Highway and Transportation Officials.

4 2016 Errata Changes to the Highway Safety Manual, 1st Edition CHAPTERS 18 Predictive Method for Freeways Where: CMF 8, fs, ac, sv, z ac, single-vehicle crashes sv, and severity z; and W s paved outside shoulder width (ft). P c,i is coputed as the ratio of the length of curve i in the segent to the effective length of the freeway segent *. The CMF is applicable to shoulder i length of curve i between the segent s begin and end ileposts for roadbed 1 and that for roadbed 2, where each value excludes the length of any coincident speed-change lane that ay be present and where the value for a given roadbed is zero if that roadbed is not curved. Table Cross Section (x) Crash Type (y) Crash Severity (z) a b Any cross section Single vehicle (sv) ) CMF 8, fs, ac, sv, fi (ac) Property daage only (pdo) CMF 8, fs, ac, sv, pdo CMF One CMF is used to describe the relationship between shoulder ruble strip presence and predicted crash frequency. fs, n, sv, ). The base condition is no shoulder ruble strips present. The CMF is described using the following equation: (18-36) f tan 05. ([ 10. P ] + ir 10. P )+ ir ( [ 10. P ] + or 10. P or ) (18-37) Where: CMF 9, fs, ac, sv, fi ac ) single-vehicle (sv) crashes; f tan P ir P or factor for ruble strip presence on tangent portions of the segent; proportion of effective segent length with ruble strips present on the inside shoulders; and proportion of effective segent length with ruble strips present on the outside shoulders. The proportion P ir represents the proportion of the effective segent length with ruble strips present on the inside shoulders. It is coputed by suing the length of roadway with ruble strips on the inside shoulder (excluding both travel directions and dividing by twice the effective freeway segent length *. The proportion P or represents the proportion of the effective segent length with ruble strips present on the outside shoulders. It is coputed by suing the length of roadway with ruble both travel directions and dividing by twice the effective freeway segent length * by the Aerican Association of State Highway and Transportation Officials.

5 2016 Errata Changes to the Highway Safety Manual, 1st Edition HIGHWAY SAFETY MANUA SUPPEMENT the ratio of barrier length ib, i to clearance distance ( W off, in, i ) should be coputed for each individual length of barrier that is found in the edian along the segent (e.g., a barrier protecting a sign support). The continuous edian barrier is not considered in this suation. Any clearance distance that is less than 0.75 ft should be set to W W is W ib W icb should be set to 0.75 ft. rier), the following equations should be used to estiate W icb and P ib. W P icb 2 ib i ib i W W +, W W +, W 2 W W near fs+ sc, ac, at, K is 10. C sdf, fs+ sc off, in, i is exp( V ) K is ib + exp( V )+ exp( V )+ exp( V ) K A B W near (18-50) (18-51) Where: W near for both travel directions and use the saller distance) (ft). in the edian. The ratio of barrier length ib to the clearance distance ( W off, in, i ) should be coputed for each individual length of barrier that is found in the edian along the segent. The continuous edian barrier is not considered in this suation. Any clearance distance that is less than 0.75 ft should be set to 0.75 ft. Siilarly, if the W near W W is W ib W near W icb should be set to 0.75 ft. For segents or speed-change lanes with a depressed edian and soe short sections of barrier in the edian (e.g., bridge rail), the following equations should be used to estiate W icb and P ib : W icb W ib, i ib, i W off, in, i is (18-52) P ib ib, i 2 (18-53) Any clearance distance ( W off, in, i ) that is less than 0.75 ft should be set to 0.75 ft. When a freeway segent is being evaluated, the proportion P ib represents the proportion of the effective segent length with barrier present in the edian. It is coputed by suing the length of roadway with edian barrier (excluding the length of any both travel directions and dividing by twice the effective freeway segent length *. For segents or speed-change lanes with depressed edians without a continuous barrier or short sections of barrier in the edian, the following equation should be used to estiate P ib : P ib 00. (18-54) 2014 by the Aerican Association of State Highway and Transportation Officials.

6 2016 Errata Changes to the Highway Safety Manual, 1st Edition Chapter 19 PREDICTIVE METHODS FOR RAMPS The input data needed for this procedure are identified in Table The first three variables listed represent required input data. Default values are provided for the reaining variables. Table Input Data for Rap Curve Speed Prediction Variable Description Xi Rap-ile of the point of change fro tangent to curve (PC) for curve i (i) a None Default Value Applicable Site Type Ri Radius of curve i (ft) b None c, i ength of horizontal curve i (i) None Vfrwy Average traffic speed on the freeway during off-peak periods of the typical day (i/h) Estiate as equal to the speed liit Vxroad Average speed at the point where the rap connects to the crossroad (i/h) 15 raps with stop-, yield-, or signal-controlled crossroad rap terinals Entrance rap, exit rap, connector rap at service interchange 30 all other raps at service interchanges Vcdroad Average speed on C-D road or connector rap (easured at the id-point of the C-D road or rap) (i/h) 40 C-D road, connector rap at syste interchange If the curve is preceded by a spiral transition, then Xi is coputed as equal to the average of the TS and SC rap-ile locations, where TS is the point of change fro tangent to spiral and SC is the point of change fro spiral to curve. b If the curve has spiral transitions, then Ri is equal to the radius of the central circular portion of the curve. a The curve entry speeds need to be calculated for all curves fro ilepost 0.0 to the end of the analysis segent. This ay include segents of an adjacent rap that are not included in the current analysis segent. For each curve, record the entry speed, the total length of the curve, and the length of the current analysis segent. Once the procedure on the following pages is copleted, return to Equation In this equation, the suation ter only includes entry speeds and radii that have a length in the current analysis segent. other curves analyzed should be ignored if they are not part of the current analysis segent. Entrance Rap Procedure This procedure is applicable to entrance raps and connector raps at service interchanges that serve otorists traveling fro the crossroad to the freeway. Step 1 Gather Input Data. The input data needed for this procedure are identified in Table Step 2 Copute iiting Curve Speed. The liiting curve speed is coputed for each curve on the rap using the following equation: 0.30 vax, i 3.24 (32.2 Ri ) (19-59) where vax, i is the liiting speed for curve i (ft/s). The analysis proceeds in the direction of travel. The first curve encountered is curve 1 (i 1). The value of vax is coputed for all curves prior to, and including, the curve of interest. The value obtained fro Equation repre by the Aerican Association of State Highway and Transportation Officials.