Road Deterioration - Shift Factors
Overview
Section titled “Overview”The following table derived from HDM5 Volume 6 explains the use of shift factors in the road deterioration models and the relationship between them.
It lists the models for each Surface Class and, for each model, describes the shift factors available and their purpose.
- CPSF: Climate Performance Shift Factor
- RMSF: Routine Maintenance Shift Factor
- MPSF: Material Performance Shift Factor
| Surface Class | Model | CPSF | RMSF | MPSF |
|---|---|---|---|---|
| Bituminous | Initiation of Cracking | Yes When the climate is getting colder, earlier cracking is expected | N.A. | Yes Crack retardation material, such as bitumen, rubber, or epoxy bitumen, will slow down cracking initiation |
| Cracking Progression | Yes When the climate is getting colder, higher crack progression is expected | Yes A higher routine maintenance level will do more crack sealing, slowing down crack progression) | Yes Crack retardation material, such as bitumen, rubber, or epoxy bitumen, will slow down the growth | |
| Initiation of Thermal Cracking | Yes When the climate is getting colder, earlier cracking is expected | N.A. | Yes Crack retardation material, such as bitumen, rubber, or epoxy bitumen, will slow down cracking initiation | |
| Progression of Thermal Cracking | Yes When the climate is getting colder, higher crack progression is expected | Yes A higher routine maintenance level will do more crack sealing, slowing down crack progression) | Yes Crack retardation material, such as bitumen, rubber, or epoxy bitumen, will slow down the growth | |
| Initiation of Ravelling | Yes When the climate is getting colder, earlier ravelling is expected | N.A. | Yes Enhanced material, such as bitumen rubber or epoxy bitumen, will slow down the ravelling initiation | |
| Ravelling Progression | Yes When the climate is getting colder, faster ravelling is expected | N.A. | Yes Enhanced material, such as bitumen rubber or epoxy bitumen, will slow down the ravelling progression | |
| Rutting – Initial Densification | N.A. | N.A. | N.A. | |
| Rutting – Structural Deformation | Yes Higher rainfall will increase the rut rate | Yes Routine maintenance directly impacts the rut rate | Yes Rutting resistance materials such as stabilised and Stone mastic Asphalt reduces rut | |
| Rutting – rut acceleration | Yes Higher rainfall will increase the probability of accelerated rutting | Yes Higher-level routine maintenance reduces the probability of accelerated rutting | Yes Rutting resistance materials such as stabilised and Stone mastic Asphalt, the probability of accelerated rutting | |
| Rutting – Plastic Deformation | Yes Higher temperatures and more hot days increase the plastic deformation | N.A. | Yes Less temperature-sensitive material decreased plastic flow (e.g. epoxy asphalt) | |
| Roughness Progression | Yes Any climate shift is most likely going to cause increased roughness | Yes Routine maintenance impacts on the roughness progression | N.A. | |
| Texture Depth Progression | Yes Higher temperatures and more hot days increase texture loss Wetter climates may also increase texture loss due to chip intrusion on the base course | N.A. | Yes Less temperature-sensitive material decreased texture loss (e.g. epoxy asphalt) | |
| PCI (Markov only) | Yes | Yes | Yes | |
| Concrete - tbd | Faulting in Joints without Dowels | |||
| Faulting in Joints with Dowels | ||||
| Spalling for JPCP | ||||
| Spalling for JRCP | ||||
| CRCP Failures | ||||
| Incremental Roughness for JPCP, JRCP, and CRCP | ||||
| Unsealed | Roughness Progression | Yes (Markov only) Any climate shift is most likely going to cause increased roughness | Yes (Markov only) Higher grading frequency reduces roughness | Yes (Markov only) Better material selection prevents roughness increase, such as potholes and corrugations |
| Effect of Grading | N.A. | N.A. | N.A. | |
| Annual Material Loss | N.A. (embedded in the model) | N.A. (embedded in the model) | N.A. (embedded in the model) | |
| PCI (Markov only) | Yes | Yes | Yes |