What Data for This Category Looks Like
Data sources for the railway and highway category primarily include road network infrastructure archives publicly released by transportation authorities, monthly operation scheduling reports, line operation and maintenance logs, and real-time traffic monitoring data. There are three types of data update rhythms: infrastructure archives are statically updated only when lines undergo renovation or expansion; monthly operation data is released each month; real-time traffic and load data is refreshed hourly. Most documents use structured tables or PDF reports with fixed fields. Core fields include line number, operating mileage, traffic volume, load rating, and maintenance cycle. Units uniformly use standard transportation measurement units such as kilometers, ten thousand person-times, and tons.
What Constraints These Characteristics Impose on Citation Source and Traceability
The data characteristics of the railway and highway category impose multiple constraints on the citation traceability process. Differences in update rhythms across multiple data sources require marking both release time and collection time during traceability. This avoids confusion between historically archived infrastructure archives and real-time traffic monitoring data. The fixed field feature of structured documents requires precise positioning to specific fields during traceability. Associating only the entire document does not meet requirements, ensuring accurate correspondence between cited content and original data. Data sources include public administrative archives and internal operation and maintenance logs. This requires the traceability chain to cover the full process of data collection, cleaning, and storage, and clarify ownership permissions for data from different sources. In addition, uniform transportation measurement units require attaching original unit information during traceability. This avoids citation deviations caused by unit conversion.
How to Configure
| Configuration Item | Recommended Value | Rationale |
|---|---|---|
recall_top_k | Top 8-12 entries | Railway and highway data mostly consists of structured entries. A sufficient number of related fields must be recalled to match queries, avoiding omission of core operation or infrastructure information |
similarity_threshold | 0.75-0.85 | Structured data has high semantic similarity differentiation. A threshold that is too low will introduce irrelevant operation and maintenance logs. A threshold that is too high will miss some matched operation data |
PARSE_FILE_TIMEOUT_SECONDS | 600 seconds | Large road network infrastructure archive PDFs may contain multiple pages of structured tables. Parsing takes a long time, so sufficient parsing time must be reserved |
UPLOAD_FILE_MAX_SIZE | 1000 MB | Annual operation log collections for a single line or cross-regional road network reports may reach large sizes. This setting adapts to single-file upload limits |
re_rank_top_n | Top 5 entries | Recalled structured data must be re-ranked to prioritize matching core query fields, such as traffic volume and load rating, which are key business indicators |
source_metadata_fields | Line number, release time, data source institution | Railway and highway data requires traceability by line, time, and release subject dimensions, ensuring citations can quickly locate the original data source |
The parameter values provided on this page are common recommended starting points for configuration. Actual values are affected by material form, data volume, and business rules. Specific issues require specific analysis. It is recommended to test on your own samples before finalizing settings.
Three Common Misconfigurations
- Phenomenon: The returned answer is unrelated to the content cited in the knowledge base, and the cited fields do not match the answer content. Cause:
source_metadata_fieldsis not configured with core business fields, orsimilarity_thresholdis set too high, causing recalled structured data to fail to match the core indicators of the query. - Phenomenon: Local testing functions normally, but citation sources cannot be loaded on external release channels. Cause:
UPLOAD_FILE_MAX_SIZEis not configured to adapt to file transfer restrictions for external access, orPARSE_FILE_TIMEOUT_SECONDSis set too short, causing large road network archive parsing to complete before results are returned. - Phenomenon: Only the knowledge base citation link is returned, and no corresponding answer content is generated. Cause:
recall_top_kis set too low, failing to recall enough valid structured data, causing the model to be unable to generate qualified answers based on knowledge base content.
How to Verify Proper Configuration
- Upload a monthly operation report for a single line, and check if parsed fields cover preset traceability fields.
- Initiate a query that includes specific line traffic volume, and verify that returned citation sources mark the corresponding release time and data source institution.
- Check system logs to confirm that the number of recalled entries matches the
recall_top_ksetting, and that model calls comply with configuration requirements. - Test the citation link on external release channels, and confirm that the original data document can be accessed normally.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-14.