Spread width
spread_width_m
Width of water spread on the roadway T (m)
Scores if within ±3% of the reference value.
Determines the width of water spread across a roadway pavement and curb flow depth using the HEC-22 Manning's equation for triangular gutter sections: T = (Q*n / (K_u * Sx^(5/3) * S_L^(1/2)))^(3/8). Used for inlet spacing design and pavement drainage adequacy checks to ensure roadway safety during design storms.
both: The model must reason numerically unaided.
Standards
One template produces many comparable benchmark tasks while keeping the scoring contract fixed.
01
The reusable contract shown on this page.
02
An archetype and site context are sampled.
03
Inputs may be hidden at harder tiers.
04
The model responds with the declared outputs.
Inputs the model receives, and the outputs it is scored on.
4 inputs
Included directly in every task prompt.
Gutter flow
gutter_flow_m3_s
Design gutter flow rate Q
Cross slope pct
cross_slope_pct
Roadway cross-slope Sx (percentage)
Longitudinal slope pct
longitudinal_slope_pct
Longitudinal road gradient S_L (percentage)
Sampled from the scenario and inferable from its description.
Mannings n
mannings_n
Manning's roughness coefficient n for the pavement surface
Derived from the archetype scenario. Hidden at hard difficulty.
2 outputs
spread_width_m
Width of water spread on the roadway T (m)
Scores if within ±3% of the reference value.
curb_depth_m
Flow depth at the curb face d (m)
Scores if within ±3% of the reference value.
Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.
All inputs given
Small urban road, all parameters given, straightforward spread calculation
All inputs given
Arterial or highway with higher flows, all parameters given
Some inputs hidden
Manning's n hidden, agent must infer roughness from road surface description
Hidden inputs
Prompt replacement text
The road is {{ archetype.description }} located at {{ archetype.site_context }}
The exact instruction and parameter contract used to generate this task, pinned to the published library source.
/workspace
Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.
1You are a senior civil engineer specializing in roadway drainage and stormwater inlet design.2 3## Problem4 5Calculate the width of water spread on a roadway gutter and the flow depth at the curb using the HEC-22 Manning's equation for a triangular gutter cross-section.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Gutter flow (Q) | {{ gutter_flow_m3_s }} | m³/s |12| Roadway cross-slope (Sx) | {{ cross_slope_pct }} | % |13| Longitudinal slope (S_L) | {{ longitudinal_slope_pct }} | % |14{% if mannings_n is defined %}15| Manning's roughness (n) | {{ mannings_n }} | - |16{% endif %}17{% if archetype_description is defined %}18 19### Road Conditions20 21{{ archetype_description }}22{% endif %}23 24{% if tool_available %}25## Available Tool26 27A roadway spread calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:28 29```bash30python3 /workspace/{{ meta.name }}_calc.py --help31```32 33You may use this tool to verify your calculations or compute values directly.34{% endif %}35 36## Required37 38Calculate the following:39 401. Spread width T (m) — the width of water spread from the curb face across the roadway412. Flow depth at curb d (m) — the depth of flow at the curb face42 43## Applicable Standards44 45- HEC-22: Urban Drainage Design Manual (FHWA)46 47## Constraints48 49- No internet access is available. Work from engineering knowledge and the provided tool.50- Use Manning's equation for a triangular gutter cross-section (SI units):51 - **Flow equation:** Q = (K_u / n) × Sx^(5/3) × S_L^(1/2) × T^(8/3)52 - where K_u = 0.376 (SI), Sx = cross-slope (m/m), S_L = longitudinal slope (m/m), T = spread (m)53- Solve for spread width:54 - **T** = (Q × n / (K_u × Sx^(5/3) × S_L^(1/2)))^(3/8)55- Flow depth at curb:56 - **d** = T × Sx57- Convert slopes from percentage to m/m before computation (divide by 100).58 59## Output Format60 61Show your step-by-step working in Markdown, including formulas and intermediate calculations. At the end of your solution, include a JSON block with your final answers in exactly this format:62 63```json64{65 "spread_width_m": <numeric_value>,66 "curb_depth_m": <numeric_value>67}68```69 70Write your complete solution to `/workspace/output.md`.71 Each generated task is drawn from one of these realistic scenario bands.
Site contexts ground each scenario in a real locale the model can use to infer hidden values.
urban_local_road
Urban local road with steep cross-slope and smooth asphalt pavement
suburban_collector
Suburban collector road with moderate cross-slope and aged asphalt surface
arterial_road
Major arterial road with standard cross-slope and concrete gutter channel
highway_shoulder
Highway shoulder with shallow cross-slope and textured asphalt surface
sydney-suburban-street-urban-local-road-preview — hard difficulty, some inputs hidden.
Urban local road with steep cross-slope and smooth asphalt pavement. sydney-suburban-street. Required outputs: spread_width_m, curb_depth_m
Scenario context and visible inputs.
Executable tool: roadway-spread_calc.py
Inputs withheld at this difficulty.
Mannings n
mannings_n
Stand-in text in the prompt
The road is {{ archetype.description }} located at {{ archetype.site_context }}
The scored JSON answer schema.
{
"spread_width_m": <number>,
"curb_depth_m": <number>
}