Poor Roads and Aggressive Driving causes Substantial Higher Fuel Consumption in Israel

Poor roads—with potholes, uneven surfaces, or high roughness—noticeably increase vehicle fuel consumption. An issue in Israel.

The main mechanism is Pavement-Vehicle-Interaction (PVI): Uneven surfaces increase rolling resistance, lead to energy losses in tires and suspension (dissipation through vibrations), and cause more frequent braking and accelerating.

The engine compensates for these losses, raising consumption. Scientific studies quantify this effect and emphasize that well-maintained, smooth roads are not only more comfortable but also more fuel-efficient and environmentally friendly—with potential savings in the billions at the network level.

Pothole on a damaged road—typical cause of increased energy loss and consumption. Severe potholes exacerbated by weather influences. Comparison of rough (left) vs. smooth asphalt surface (right). Finally, the “embodied carbon” of paving a new road is often offset within 1–3 years by the fuel savings of the vehicles using it.

Bad Roads

The excess consumption depends on the severity of roughness (measured by the International Roughness Index, IRI in m/km), vehicle type, speed, gradient, and climate. Typical values from studies:

• 5–20% excess consumption with significantly increased roughness → Mechanistic models show that unevenness increases rolling resistance and vibration losses (MIT Concrete Sustainability Hub, 2012–2021; Louhghalam et al., 2015).
• 8–18% savings with smooth roads → Practical measurements on compact cars showed 8–18% less consumption on smooth vs. rough pavements (XenomatiX, 2023-based on measurement data).
• Approx. 10% reduction through resurfacing → A before-after study (Transportation Research Part D, 2025) found that a 27% IRI reduction led to about 10% less consumption and CO₂ emissions—especially uphill.
• 1–6% per IRI unit (1 m/km) → Calibrated models estimate 1–4% excess consumption per IRI increase for passenger cars (up to 6% at low speeds); for trucks often 1–3% (Chatti & Zaabar, 2012; Oregon DOT, 2021; HDM-4 model).

Passenger cars react more strongly to roughness (through suspension dissipation), while trucks are more affected by deflection (pavement deformation). In cold climates or at high speeds, the effect can vary.

The relationship between fuel and roughness

The relationship between fuel consumption and road roughness can be described by the following equation:

Where:

\(FC\)

is the actual fuel consumption.

\(FC_{\text{base}}\)

is the consumption on a perfectly smooth road.

\(\alpha\)

is the sensitivity coefficient (typically 0.01 to 0.03 for passenger cars).

\(\Delta IRI\)

is the increase in roughness (measured in m/km relative to a smooth baseline).

Measurement of roughness with IRI—profile and index calculation. Example of IRI progression graph and roughness profile. Road roughness measurement using laser or LiDAR equipment.

Key Studies and Sources

• Chatti & Zaabar (2012) — Calibration of the HDM-4 model for U.S. conditions; roughness is the dominant factor for excess consumption (NCHRP Report 720, Transportation Research Board).
• Louhghalam et al. (2015) — Mechanistic model for roughness-induced dissipation; identifies IRI and waviness as key parameters; up to 15–20% influence in extreme cases (Transportation Research Record).
• Wang et al. (2019/2025) — Before-after analyses of resurfacing; 10% savings through smoother surfaces (International Journal of Sustainable Transportation; Transportation Research Part D).
• MIT Concrete Sustainability Hub (2012–2021) — Roughness and deflection cost U.S. drivers billions in extra fuel annually; smooth, stiff pavements (e.g., concrete) save 3–4% in truck networks.
• XenomatiX (2023) — LiDAR-based measurements; 11% excess consumption on rough vs. smooth roads for passenger cars.

Additional models (e.g., RSI model, random vibration theory) confirm: Roughness causes measurable dissipation in the suspension, which directly translates into higher consumption.

Good Roads

Additional EffectsBeyond fuel, emissions (CO₂, particulate matter), tire and vehicle wear, and accident risks increase. In the U.S., PVI causes billions of dollars in additional costs and millions of tons of extra CO₂ annually (MIT CSHub). Smooth roads enable more consistent driving and reduce aerodynamic losses.

Bad Driving

Aggressive driving. An issue in Israel. What do scientific studies say? Aggressive driving—characterized by rapid acceleration, hard braking, high speeds, and frequent lane changes—leads to significantly higher fuel consumption. Scientific studies consistently show excess consumption of 10–40%, depending on traffic conditions and vehicle type. The excess consumption varies greatly by situation: Conversely, calm, anticipatory driving styles (eco-driving) typically save 5–20% fuel.

• In stop-and-go traffic (urban): 10–40% excess consumption.
• On highways: 15–30% excess consumption.
• On average: Often 20–40% in mixed conditions.
• Extreme cases: Up to 137% excess consumption in older studies with extremely aggressive styles.

Key Studies and Sources

• U.S. Department of Energy & MIT/ORNL (2017): Aggressive driving reduces efficiency by 15–30% on highways and 10–40% in urban traffic—based on models and real-world tests.
• Oak Ridge National Laboratory (ORNL, 2017): Confirms a greater impact than often assumed; especially in hybrids due to limited energy recuperation during hard braking.
• Belgian study (De Vlieger et al., 2000): Up to 40% excess consumption from aggressive driving compared to normal style.
• Polish study (2020): Aggressive driving increases consumption by 30–40% in urban areas, less on highways.
• Additional (e.g., 2023 machine learning study): 23% excess consumption in construction zones and curves due to aggressive maneuvers.

Conclusion: -50% is possible

The connection is robustly supported by science—investments in road maintenance pay off quickly through fuel savings and lower emissions. Drivers can help by maintaining proper tire pressure and driving anticipatively. The smoother the road, the less aggressive, the more efficient and sustainable the driving.

Overall, with good roads and non-aggressive driving -50% cost reduction is possible. Approximately 10,000 NIS are spent per year per car (assuming 15,000 km annual mileage). With good roads and non-aggressive driving, this could be reduced to around 5,000 NIS. Maybe a thought worth.