SHV POSTING Bala Sivakumar HNTB Corp. New York

T-18 2015

What are Specialized Hauling vehicles (SHVs)?

• SHVs are closely-spaced multi-axle single unit trucks introduced by the trucking industry in recent years.

• Examples:

• Dump Trucks

• Construction Vehicles

• Concrete trucks

• Solid Waste Trucks

• Other Hauling Trucks

FEDERAL TRUCK SIZE AND WEIGHT LIMITS

1. Single Axle Weight : 20,000 lbs

2. Tandem Axle Weight: 34,000 lbs

3. GVW : 80,000 lbs

4. Federal Bridge Formula B

SHVs in the MBE comply with federal weight laws including Formula B

𝑊 = 500𝐿𝑁

𝑁 − 1+ 12𝑁 + 36

4-AXLE DUMP TRUCK

5-AXLE DUMP TRUCK

6-AXLE DUMP TRUCK

7-AXLE DUMP TRUCK

LIFT AXLES UP

FEDERAL BRIDGE FORMULA B

• SHV trucks may weigh up to 80,000 lbs and meet Federal Bridge Formula B

• Closely-spaced axles could cause load effects that exceed the stresses induced by HS-20 and AASHTO Legal Loads (by 50% in certain cases).

• Load rating and posting bridges for Types 3, 3S2 and 3-3 is insufficient to ensure safe operation for SHVs.

NEED FOR SHV LOAD MODELS

•AASHTO Type 3 posting load is not representative of

the newer SHV legal loads.

• SHVs may be overstressing non-posted bridges.

• NCHRP Project 12‐63 (Report 575, 2007)

TYPE H 15

TYPE HS 20

TYPE 3 UNIT

TYPE 3

Weight = 50 Kips

AASHTO SHV LOAD MODELS (2006)

NOTIONAL RATING LOAD (NRL)

Enforcement Question

Can an SHV tow an empty trailer to avoid SHV limits?

FHWA Guidance – No! Such a ruse would not suffice to avoid bridge load posting.

FHWA SHV MEMORANDUM

• November 15, 2013 requiring every state to post bridges for SHVs that do not pass a load rating analysis for these vehicles

Unless:

• The State verifies that State laws preclude SHV use

• The state has its own rating vehicle models for legal loads that envelope the applicable AASHTO SHV loading models.

FHWA MEMORANDUM - TIMELINE

• Category 1 BRIDGES – No later than December 31, 2017

• ASR/LFR Opr. Rating for:

• Type 3 < 33 tons

• Type 3S2 < 47 tons

• Type 3-3 < 52 tons

• LRFR Rating Factor for:

• Type 3. Type 3S2, Type 3-3 < 1.3

• Category 2 BRIDGES – No later than December 31, 2022

• All other bridges that are not in Category 1

2015 AGENDA ITEM T18-1 Addendum to AASHTO MBE C6A.4.4.2.1.b and C6B.7.2

GOAL:

• To utilize available controlling ratings for the design or AASHTO legal trucks to screen existing bridges that need to be rated for SHVs.

• Eliminate bridges that do not need to be rated for SHVs

AGENDA ITEM T18-1 SHV SCREENING CRITERIA:

• Bridges having an HS20 Operating RF > 1.20 need not be rated for SHVs.

• Bridges with a min. Operating RF > 1.35 for the AASHTO legal trucks under ASR or LFR, or

• Legal RF > 1.35 using LRFR, would have adequate capacity as follows:

• SU4 and SU5 for all spans

• SU6 for spans above 70 ft

• SU7 for spans above 90 ft

AGENDA ITEM T18-1 SCREENING WITH HS20 RF > 1.2: REQUIRED DESIGN RATING FACTOR AT THE OPERATING LEVEL

Min HS20 RF SPAN SU4 SU5 SU6 SU7

20 1.00 1.05 1.10 1.10

30 1.00 1.05 1.15 1.20

40 0.95 1.00 1.10 1.15

50 0.90 1.00 1.10 1.15

60 0.85 0.95 1.05 1.15

70 0.85 0.95 1.05 1.15

80 0.85 0.95 1.05 1.15

90 0.85 0.95 1.05 1.15

100 0.85 0.90 1.05 1.10

110 0.80 0.90 1.00 1.10

120 0.80 0.90 1.00 1.10

130 0.80 0.90 1.00 1.10

140 0.80 0.90 1.00 1.10

150 0.80 0.90 1.00 1.10

160 0.80 0.90 1.00 1.10

170 0.75 0.85 0.95 1.05

180 0.75 0.85 0.95 1.00

190 0.70 0.80 0.90 1.00

200 0.70 0.80 0.85 0.95

AGENDA ITEM T18-1 SCREENING WITH RF > 1.35 FOR AASHTO LEGAL TRUCKS:

MINIMUM GOVERNING LEGAL RF TO HAVE SHV

RF > 1.0

SPAN SU4 SU5 SU6 SU7

20 1.20 1.25 1.30 1.30

30 1.25 1.35 1.45 1.50

40 1.20 1.30 1.40 1.50

50 1.15 1.25 1.40 1.50

60 1.15 1.25 1.40 1.50

70 1.05 1.20 1.30 1.40

80 1.00 1.15 1.25 1.35

90 1.00 1.10 1.20 1.30

100 0.95 1.05 1.20 1.30

110 0.95 1.05 1.15 1.25

120 0.90 1.00 1.15 1.25

130 0.90 1.00 1.10 1.20

140 0.85 1.00 1.10 1.20

150 0.85 0.95 1.05 1.20

160 0.85 0.95 1.05 1.15

170 0.85 0.95 1.05 1.15

180 0.85 0.95 1.05 1.15

190 0.80 0.90 1.05 1.15

200 0.80 0.90 1.00 1.10

SHV RATING & POSTING

• Many states have been load rating for SHVs since

2006; results used for “Informational Purposes”

• The MUTCD only has one sign (R12-5) that has

silhouettes of 3 legal trucks for load posting

• It is up to each state to determine the language to be

used on the posting signs for SHVs.

POSTING SIGNS

Single Tonnage Posting for SHVs • If a single tonnage for posting for all SHVs is

used, the posting will be governed by SU4

• SU4 is the most compact of all SHVs

• May be too conservative as SHVs are purposely configured for maximizing load

• Posting needs to strike a balance between simplicity and not being too restrictive

Oregon DOT Category 1 Bridges

• Total of 933 Category 1 Bridges (to be load rated by 2017) out of 8035 total

• 167 State Bridges

• 729 Local Agency Bridges

Oregon DOT Category 1 Bridges

• ODOT policy for SHVs notes that:

• Before load posting any bridges with low SHV ratings, perform additional review and advanced analysis steps

• Improved load distribution

• Material tests

Oregon DOT Signs for SHV Posting

• Oregon DOT (ODOT) appears to be the first to propose posting bridges for SHVs.

• ODOT is also engaged with industry to inform them of potential impacts of this policy.

• ODOT has proposed signage for posting bridges for SHVs.

ODOT Proposed Signage for SHVs. Rider below the 3 vehicle sign when posting is needed for the 3 legal loads and SHVs

ODOT Proposed Signage for SHVs. Sign when posting is not needed for the 3 legal loads but required for SHVs. Restricts single unit trucks only.

IDAHO Study

• Over 500 bridges rated for the Notional Rating Load (NRL)

• 17 that would otherwise not require posting rate low for the NRL

NEW YORK SHV SCREENING Using available records with HS20 ratings

NY Partial Inventory Used in the SHV Screening BRIDGE TYPES LOCAL STATE TOTAL

P/S BOX GIRDER 1167 668 1835

P/S MULTI-GIRDER 216 137 353

RC SLAB 315 288 603

RC TEE BEAM 21 64 85

STEEL MULTI-GIRDER 3032 3116 6148

TOTAL 4751 4273 9024

SCREENING FOR HS20 OPERATING RF < 1.0

NYS Bridges with Operating HS20 RF < 1.0

BRIDGE TYPES LOCAL STATE TOTAL

P/S BOX GIRDER 7 2 9

P/S MULTI-GIRDER 1 0 1

RC SLAB 6 0 6

RC TEE BEAM 4 1 5

STEEL MULTI-GIRDER 297 6 303

TOTAL 315 9 324

SCREENING FOR HS20 OPERATING RF < 1.20 “MBE SHV SCREENING ”

NYS Bridges with Operating HS20 RF < 1.20

BRIDGE TYPES LOCAL STATE TOTAL

P/S BOX GIRDER 15 7 22

P/S MULTI-GIRDER 2 1 3

RC SLAB 15 1 16

RC TEE BEAM 6 6 12

STEEL MULTI-GIRDER 596 59 655

TOTAL 634 74 708

SCREENING RESULTS

HS20

CRITERIA

LOCAL STATE

INVENTORY HS20 < 1.20 INVENTORY HS20 < 1.20

4751 634 4273 74

SHV SCREENING USING HS20 OPR RF < 1.20

13.3% OF LOCAL BRIDGES

1.73% OF STATE BRIDGES

Posting for SHVs • There is a need to develop SHV posting signs that are

concise and easily understood.

• Posting signage for SHVs may require national and/or regional standardization.

• A consensus among states on how to post for SHVs is an important first step.

• Need for outreach to stakeholders in the trucking industry to inform them about SHV posting